If it is anything like a 94-96 in the trunk in the harness that runs along the left rear fender there is going to be a plug that isn't plugged to anything, stick a piece of wire in there to short or jumper the pins together and the locks and trunk solenoid will cycle once to tell you it is in program mode, hit one button on the remote only once, if it works the locks will cycle again saying it is programmed, remove jumper wire and test it out.
Looked in a 93 FSM and you may have to turn the key on.
ISSCA member # 2344
Hoosier INC Member
1994 Chevy Caprice 9C1, 126,000 miles, T56, 4.10's