Is the wiper motor still working? I would start by removing the wiper arm and trying the wiper. Check to see if the post that goes through the door is perpendicular or bent downward. You can prop a small 2X4 under the wiper post and bang it up with a 16 ounce hammer???

If the motor no longer works, with the arm off, you might have damaged a lot more than just the wiper arm.

I have removed the rear panel on my 1998 too many times. Unfortunately, every time I take it off, I manage to break a few plastic clips which requires a trip to the dealer for replacements.

Body shops are used to dealing with things like this and are much cheaper than new car dealers.

Klaus
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Always willing to listen, just not able to take direction.