Fortunately the other side was still attached, and I was able to copy the alignment
Once I'd figured it out, removing and refitting the bushes was actually easy. I've bashed together a little guide for anyone else facing the same problem, perhaps applicable to other cars.
You need a sturdy vice, a 32mm socket, a 21mm socket, a big hammer, a chissle, a blow torch, a hack saw and an angle grinder. The 32mm socket needs to be deep enough to accommodate the rubber part of the front bush.
Before you start, put the front bushes in the freezer!
Front Bush
Removal
Place the wishbone upright in the vice with the front bush facing towards you, and the P bush at the back. Place the 32mm socket facing in the way in front of the front bush. Place the 21mm socket behind the front bush facing backwards into the bush, and then sandwich the lot in the vice. Do the vice up really tight, the 21mm socket will start to sink into the bush. Heat the outside of the wishbone around the bush with the blow torch, this will start to melt the rubber inside. You should then be able to tighten the vice up a bit more, the bush should start to move forward into the 32mm socket. Repeat a cycle of heating and turning the vice, the bush should move forward a little each time until it comes out into the 32mm socket.
You are now left with the metal sleeve stuck inside the wishbone. Remove the blade from the hack saw and put it through the sleeve and re-attach the saw. You can then cut a groove the whole length of the sleeve. Try and cut it all the way through without damaging the wishbone. Remove the hacksaw. The sleeve has a protruding lip at the rear of the bush, take a hammer and chissle and whack this hard a few times all the way round, it will start to fold inwards. The groove you cut will allow the sleeve to collapse in on itself and it should come out easily. The first sleeve I did came out after only 3 whacks.
Refitting
I used some fine sandpaper and WD40 to clean up the inside before fitting the new bush.
Heat the outside of the wishbone with the blow torch until it's very hot. Take the front bush from the freezer, it should be very cold. I put some copper slip on the outside to lubricate, or some silicon grease might do. Get it started with a couple of bashes with the hammer, and then put it in the vice. Do the vice up as fast as you can as the hot wishbone brings the bush up to temperature very quickly, causing it to expand! The more progress you make in the first few seconds the better. After that it's just a case of some muscle to push it in the rest of the way. You may need to whack the handle of the vice round with the hammer to finish it off.
I did the first wishbone without freezing, it was significantly more difficult, freezing is must. While the bush is cold, it goes in very easily.
Front bush done
"P" Bush
Easy compared to front bush.
Removal
It the bush is still attached, put it in the vice and turn the wishbone a few times until it breaks free. You will be left with the metal sleeve. Cut a groove along this with an angle grinder, trying to cut it all the way through without damaging the wishbone. Then take the hammer and chissle and open the groove to split the sleeve apart. It should then come off easily.
Refitting
I put the bush in a jug of boiling water, but this didn't seem to help any. Use copper slip or silicon grease to aid fitting, and clean the area of the wishbone up with WD40 and fine sandpaper.
It should just be a case of whacking it on a few times with the hammer, taking care of the alignment. On the 405, there should be 254mm between the 2 bushes. Take care not to whack it on too far!
Job's a good 'un
GSF are a lot cheaper, did they last ok? Some people say avoid pattern part bushes. Did you replace the nylon lock nuts? If so, where did you get them?
