Use some rust breaker overnight before you do the swap. You may need a breaker bar and pipe to loosen the main nuts. Just use a floor jack under the pan to slightly lift the motor (once loosened) and replace the mounts one-at-a-time. Shouldn't take any more than an hour, tops.
BTW: If anybody's interested, I've got a set of late model convertible (stiffer) mounts for sale that just came off my car. Only about a year old, in perfect condition. I've gone with ASP solid mounts. These will fit '87-93 cars. Check my website for details.
------------------
Jeff Chambers
Trophy Stock #3
11.97 Seconds / 114.5 MPH
Chambers Racing Team