www.volvospeed.com has a maintenance section called Bay 13 that has clear instructions.

The old one will come out with a hacksaw blade. You don't need to cut it all the way through, just cut a good grove and then slip in a flat head screwdriver to crack it all the way. After that, the old bushing will come out.

I installed the non OEM bushing that comes in two halves. Use some hair gel to help get it into place, after that you simply force the arm bracket into place and then slip the bolt in. The entire procedure takes about an hour or less, there's no need to remove the arm/bracket that is attached to the firewall other than the bushing bolt.