I also recommend taking it to a shop. Not sure if the trooper is the same as the rodeo but on my rodeo the rear LCA bushing is in the frame, not the arm. I had it done at a local shop, was around $500 in labor to do both sides plus front wheel alignment (I supplied the parts). Took the guy all day to do it and he said he never wants to do another set of bushings on an isuzu again. Mine doesnt even have that much rust. If it was that bad with a lift and all the propper tools I'm glad I didnt attempt it on my own in the parking lot.

--Dave

1999 Rodeo LS 3.2 4x4 5 Speed
32x11.50-15 BFG T/A KO on US Wheel 94 series
3" Lift - Rancho 9000x
Rear No-Slip Locker
Flowmaster 50 series SUV 2.25"

There is a very fine line between "hobby" and "mental illness." - Dave Barry