Speakers on 91 DSM

I'm buying speakers. Anyone know what size the door speakers and rear seat speakers are? I keep searching for them, but every site has a different number. I'm worried of taking off the guard of the speakers to measure them. If you don't know the size, can you tell me how to get the guard off? Do they just squeeze to come off, pull off, does the whole door pannel have to come off or what?

u gotta take the whole door panel off

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