Front and rear door panel removal

It is actually pretty simple. Just use a Phillips head screwdriver to undo the few screws that you see (one's behind the handle, cannot remember where they all are). There are probably four or five. Once you get all of them out, use a flat head screwdriver to pry the door panel off. Then you just have some electrical connectors to deal with. Takes about five minutes if you know what you are doing, maybe twenty if you do not know.

Thanks and where would I purchase speaker brackets for 5.25 two-way speakers for both front and rear doors?

Junk yard, eBay, Amazon, or a car audio shop. Junk yard would be the cheapest. Personally, I just use a drill and fashion my own screw holes.