How do you disable power door locks that are making grinding noises on 1992 cadillac deville?

A more or less permanent (though difficult) solution might be to remove the door panels and disconnect the lock actuator wire connectors on the offending locks. Though if you have the door open, you might want to fix the locks instead. If the motors keep running but otherwise work OK, the solution might be to check and clean the limit switches. Alternatively, you might need to replace the door lock actuators.

For a quick way to silence the locks, you can pull fuse #24, which will disable all the power door locks, as well as the power seats, the rear defogger, and the remote keyless entry system.