I've had a reasonably successful afternoon. Not as successful as I'd hoped for but I'm pleased with what I've done.

First I removed the rear arm... easy. Just let the air out of the spring, undo all the bolts, support the hub and take the arm off. One of the bolts is also an adjuster for the alignment so at the very least make a note of its position so you can put it back in the same place. It'd be a very good idea to get the alignment checked after doing this job regardless. With the arm off I was able to get a better look at the problem:



Eww. Nasty. The other other bush is still in very good condition though.

I used the normal procedure for removing bushes, that is, carefully cut through the shell and tap it out. I'll emphasis the "careful" aspect here because the suspension arm is aluminium and you don't want to damage it. On the upside though, the shell of the bush is aluminium too, so it's very easy to crush it to get it out. The suspension arm is incredibly light as it's hollow:



And that opening in the arm is very important. IMO that's actually the problem here, the shell of the bush is very soft and had allowed the rubber to "explode" into the arm:



I think the bush would last a hell of a lot longer if it wasn't for that hole. What's done is done though and the new bushes aren't expensive so not a big deal.

Getting the new bush in is a bit tricky though. First it needs to be compressed right down. It starts off much larger than the opening in the arm and compressing it pre-loads the rubber. A few - I used three - Jubilee clips do the job here. Then carefully press the bush in. I did it with a Heath Robinson arrangement in a vice but a hydraulic press would make it a lot easier. I'm going to invest in one before the next job. Remember that the shell is aluminium and hence very easy to distort so just whacking it with a hammer is not going to be a good plan. It took me ages to get the bush all the way in but I managed in the end:



I was running out of time so didn't do the other bush on that arm today. It looks to be in perfectly good condition but while I had everything apart I found that the balljoint is knackered too so the arm's going to be coming off again soon anyway and I'll do it then. Most likely next weekend. I'll do both sides and I'll get the alignment done after that.