there have been plenty of topics on this. I have clunking form the back also so I researched this before. (search: Knuckle Bushing)

General consensus was it is a PITA to do. But you have to do it yourself cuz a shop will charge you an arm, leg and a first born. Look how many nuts and bolts they have to unscrew and than disconnect brakes and the whole assembly... $$$$

I don't think they will change the price if you get it out yourself and ask them to just press it back in. I think it would be a good idea to shop around.

Well get back to us with the results.

P.S I wonder if there is a portable press that can press the Knuckle Bushing in on the spot?