Changing the Cush Bearings on a Honda CG 125

Okay, I know its an obvious title, but I'm hoping that it may help someone who is doing a search one day.  There is very little out there with regards to showing how to change cush bearings on a CG 125 considering how popular and common these bikes are.  So, I will try to explain how they work and why they are there, and how to replace them.
First off, to explain what the cush bearings are, and what they do.
My bike had this thing where if I touched the throttle, even a little bit, the bike would jerk forward underneath me.  Also, if I was pottering down the road at a constant speed, the bike would feel like it was stumbling along - almost like it was misfiring.  After doing a bit of research, I discovered the things called cush bearings might be the culprit.
Basically, they are rubber bushings that sit in the hub of the drive wheel, acting as a shock absorber for the transition of power from the rear sprocket to the wheel.  On a push bike, there is no absorption; the power is directly transferred from the sprocket to the wheel hub.  Motorcycles have the bushings to help make power delivery smooth, reducing stress on the drivetrain, whilst allowing power to transfer to the wheel.
On the Honda, there are four bushings pressed into the rear wheel hub, and the sprocket has four pins that sit in the bushings.  The sprocket is not attached or bolted down in place, it is held only by the chain and the cush bearings.
To access the bearings, you have to remove the rear wheel.  To do this, I first put the bike up on a paddock stand.  Which caused my first problem....  The exhaust pipe prevents access to the swingarm, where the paddock stand lifts the bike!  It sits lower than the swingarm, and is about 15mm away from it, so I had to remove the exhaust to get it up in the air.  A bit of a pain, but seeing as it's one bolt at the back and two capped nuts at the engine, it's pretty easy to do.  (Plus it gave me a chance to examine the pipe, and clean it up - discovered a small hole in the bottom and some rust underneath.)
With the bike up in the air, I then removed the chain guard, and disconnected the left shock absorber.  I then detached the rear brakes, and the brake bar - this is the metal bar connected to the brake assembly hub and the swingarm - it basically keeps the brakes from spinning along with the rest of the hub.  I pulled out the axle, which is held on by a simple nut - there is a spacer on the exhaust side of the wheel, which will fall out and roll under your workbench if you're not careful.

I pushed the wheel as far forward as I could (towards the engine).  This gave enough slack on the chain for me to pull the chain off the rear sprocket.  I also pulled the front sprocket cover off; this is just a plastic cover held on with two bolts, sitting next to the crankcase.  When it comes off, there is also a chain stay that comes with it - this is a crescent shaped piece of metal that keeps the chain close to the front sprocket.  Here is a photo of the front sprocket, with the chain stay highlighted with an arrow.  Note the copious amount of chain grease that's been flung off the chain.

It may be worth noting at this point, that if you need to change the chain, this is a good time to do it.  I had a new chain, ready to go on, however after looking at the instructions, I discovered I would need a chain rivet breaking tool to get the old one off.  I decided at this stage I would just put the old chain back on and change it when I had the correct tools (post to follow....).
So I struggled for a while to get the rear wheel out from underneath the tail of the bike; it was a real tight fit.  I ended up having to grab the tail of the bike and lift it off the paddock stand with one arm and pull the wheel out with the other.  I'll tell you now, if you pull the wheel out on the exhaust side, it will come out easily - I learned this later when putting the wheel back on.
I then put the rear wheel on the bench and removed the sprocket, exposing the worn cush bearings.

They weren't as bad as I thought they might be, but still pretty far gone.  I discovered they were pressed in, and tried removing the rubber from one of them, to see if I could pry it out.  I spent ages chipping away at the rubber - it didn't come out easily, and the end result was that I was no further ahead.  Deciding to spend some time thinking about a way out of this, I gave the hub a bit of a clean; it was heavy with old grease, and it came out pretty nice.
I arrived at the conclusion that I would have to spin it out by force.  I soaked the bearing in WD-40, then took a large pry bar, and hammered it into the bushing.  I was then able to spin the whole bearing, and it slowly came out.  Success!

So, I decided I would make a video of the process.  I hammered the bar in, and spun out the bearing.  I then noticed that I managed to crack the casing of the hub.  Shit.

I was able to gently tap it back into place (more or less), and it seems to be okay - the bike doesn't seem all that bothered.
Here's the damage...

This shows where the prybar dented the inner lip the bushing sits in.

Here is the outside of the housing.
The lesson here is that if doing this with a pry bar and hammering it in, make sure the points of the pry bar and up against the thicker parts of the hub, not the weaker outside edge.

I then removed the other bearings, and slid the new ones in.  They needed gentle tapping to get them flush; I placed a small piece of wood on top of the bearing and hammered the wood.  This prevented me from damaging the new bearing.

I also wanted to replace the front and rear sprockets, however I could not get the cush bearing pins out of the old sprocket.  I didn't want to damage them, so I thought I'd leave them in and reinstall the old rear sprocket. I could investigate the purchase on new rear pins later.
I did replace the front sprocket, though.  This was easy - with the chain pulled off, it was two bolts holding a retainer in place, and off came the sprocket.  I did notice there was a lot of play in the sprocket on the shaft.  I wasn't sure if a new sprocket would make a difference or not.
Also, the kit I got provided a 15-tooth front sprocket instead of the original 14-tooth.  This would in theory give me a higher top speed, but would take away some acceleration as the bike would have to work harder to get the revs up.  We shall see what the end results of that are.
Installation is reverse or removal, as they say.  After putting it all back together, it was a matter of aligning the rear wheel (easy to do with the marks on the swingarm).  A quick test drive, and I noticed a difference right away - accelerating away from a stop was smoother, and steady speeds were better - not perfect though, but that's because of the old chain - it needed replacing as well.
Overall, it wasn't a terrible job - if I hadn't wasted so much time trying to figure out how to get the old bearings out, I think the job could be done in just a few hours or less.  Plus it really showed me the inner workings of the bike; there is nothing wrong with getting your hands dirty and learning how your bike works.  It gave me a chance to also check for other signs of wear and anything else that might be dangerous or might need attention soon.
I will follow up with the chain replacement process, and a report on how the sprocket change has affected drivability.