I have a bushing driver set I use to install them. If your super careful you can even use a piece of pipe that's the right o.d. I did it that way for a few yrs. before I bought the bushing driver set. Also note you need to stake the bushing in place or it's possible it'll spin. That might be what happened to it in the first place. Someone may have replaced it and not staked it in place.
BTW: you also need to pull the front pump to disassemble it and clean it cause I'm sure if the bushing is chewed up there is trash in the pump. May have even chewed up the gears. It doesn't take but a few seconds of running metal through the system to chew stuff all up. To take out the front pump and not have the clutch packs fall out tighten up the front band adjuster and it'll hold the clutch packs in place. Then pull out the pump, take it apart and clean it, check the gears and if their worn replace them, install the new bushing and seal and assemble the pump. Then install it and re-adjust the front band. It probably needed adjusted anyway. Also check the filter as the chewed up bushing probably fill the filter with metal.
