looks like you have to take off the panel behind the door lever, a screw that holds the panel on near the window switches and a panel near the top hinge and then you can pry the door panel off.
The bolt patterns were the same on the speakers I was installing (older Alpines) and the pre-drilled holes in the door frame for the OEM speakers, so replacement was a snap. The metal is fairly thin though so drilling a pilot hole or even using a metal screw directly would have been easy. But remember 6x9 up front, 6x6 in the rear. If you want to g0 6x6 up front you'd obviously need an adapter plate (included in the price if you order from Crutchfield).
As I mentioned, rears are 6x6, fronts are 6x9. My 6x9 Alpines went in the front 6x9 openings without issues...sorry...no pics.