I have an '83 coupe and recently encountered the same problem. You need to remove the whole dashboard cover in order to get at the speakers. The places that I can remember to look for screws are each side of the cover facing the doors, the top of the inside of the glove box (there is a small hole there for access), the top of the place where the speedometer goes, and in each defroster cover. Once all the screws are out the dashboard cover is still held on by clips but all you have to do to get it off those is pull it towards you. Warning: I probably did not list all the screws so just remove the ones I talked about try to pull it off and see where it is being held down. I will never understand why cadillac thought that so many screws were necessary to hold that thing on. Honestly the clips are pretty much enough. Oh yeah, once you get to the speakers have fun getting the screws holding them down out. Tools necessary for undertaking: phillips head screwdriver, and a socket set with exstensions and driver bits.