They're 6x8s front and rear, you need to remove the door panels to get at them. Even with the "premium" stereo, they aren't designed to handle more than 25 watts per channel.
As for how to remove the panels, I'm sure if you dig there is at least one "how to" around here, but I keep a Chilton's manual handy for just such things ($16). An easier approach yet would be you to get adapter plugs from Crutchfield, and they'll throw in instructions for removing the door panels with them! In addition to not having to splice wires, this prevents you from wiring the speakers incorrectly.
Originally posted by Fat Mike:
What type of speakers came with the 95 GL? How many watts? I know the speakers that came with my car suck, but I'm just curious. Also, how do I remove the speaker covers on the doors so I can actually install new speakers??? Is there a tutorial somewhere that can help me?