Do you mean the ECM bypass for timing purposes? If you only want to reset the ECM, look down near the battery and you should see an orange wire with a round cylindrical connector. Disconnect this for about 30 seconds then plug it back. That will cause the ECM to have to relearn sensor information. If you replaced the distributor and need to re-time the car, then the ALDL connector is behind the cigar lighter trim plate. Remove the trim plate using a small torx bit.
Fashion a paper clip into a U. Start the car and let the engine come to operating temp. Turn off the ignition. Always be sure the ignition is off when inserting or removing the paper clip jumper.
Now, follow the directions in this link:
http://gafiero.org/timing.shtml