1991 Volvo 240 - How do you replace the lock set in the driver's door I have the interior door panel off but I can not figure out how to remove the lock.?

Remove the 2 screws on the side panel. These hold the lock cylinder support in place. If you have power locks, also remove the collar (connected to the central locking switch harness) from around the lock cylinder. The lock can easily be pulled out now.