How do I replace the motor mounts in 1995 T-Bird ?

I would think you would want to loosen the nuts/bolts, and jack the engine up slightly from underneath the car to remove the old mounts out and place the new one in.

The best way to access the mounts on your 4.6L is to remove the alternator and use a fixture to raise and support the engine from above by the alternator bolts. Harbor Freight has a fairly inexpensive one that will do the trick. It will also save fingers from being severed when the engine slips off of the floor jack and give you room to work under the car. Use the right tool for the job.