Update: 1993 Convertible (coupe rear), but sounds like it is the same on hatches.
Unless you have already removed the drivers side tow hook, you will have to either remove the bolts (good luck - mine were rusted to hell) or cut it off. I used a Saws-All from below, it took 3 minutes. I didn't even have to jack up the car but I did have to remove the exhaust back part.
The rear bumper will not slide out with the core unless the tow hook bracket is cut or unbolted.
Seems like this step is left out of most threads on rear bumper removal, perhaps because it is frequently already cut off for exhaust or other reasons.
