I replaced all of the front wishbone bushing bearing supports at the weekend and it turned out to be a pig of a job. First of all, all of the nuts on the subframe bolts were well seized on and heat couldn't be safely applied because of their proximity tot he rubber bushing. They are 16mm hex but my sockets are bi-hex and may be past their best and you can only get an open-ended spanner on the rear bolt anyway. I got the best fit with a 5/16" Whitworth!
Once the bolts were out of the way the next problem was getting the old supports off the spindles. They also were well seized on. The front ones weren't too bad but the rear ones are not very accessible but eventually succumbed to a hammer and chisel.
Getting the bolts back through the spindles wasn't too easy either because the bush is in torsion.
If I was doing the job again, I would undo the 3 bolts at the ball joint, remove the drop link from the roll bar, undo the butterfly bushing and remove the control arm completely. It would have been about as quick and a lot less hassle.