You can do anything you want to the old bushing as long as you don't hurt the control arm. Pushing the new one in is another thing. It is best done with the special tool designed for it but there are numerous universal bushing driver arrangments that do fine. You need to be sure the bush is in the proper orientation to the control arm (its very important). After assemble don't tighten the control arm bolts untill sits at curb height.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician