Impressive work, welded sections etc...
But they involve dropping the arm to give access to the rear?
As Newent proved, that's a process that can be a total mare to sort out "if" the arm moves out of range of the bolt holes. Jimbobs ESP, although not helped by Daz's hair trigger jack.

.

For others reading...
IMO jack the arm and hold in place, unbolt the plate, don't let the arm move. Pull the bush out, via what ever means, small baring puller, claw hammer and lever out square, levers, bars, what ever. Then press the new one in with another jack or febi ones will welt in with a big bat, then bolt the bugger up again. Provided the arm doesn't move the pad doesnt need to be touched, therefor the arm can stay put.
Half hour a side, with alot if practice. Really need to update the guide. It's far too long winded tbh