damn i need to write something up and have a mod sticky it, cause this is the 1434167256127856231978 time i have written it
do as mazda3zoom said about taking off the door panel, you don't really need to take the tweeter cover off, and i would suggest sound deadening cause there is a lot of s*** that rattles... trust me... (225 watts rms to each door) make sure you re use the rain gaurd that covers the stock speaker or you will end up with rusted out wires and s***.... it just pulls off of the old speaker i used silicone adhesive to hold it to my new speakers, if you are putting a 6.5 in you will need a mounting plate, not a big deal at all as most companies either supply them with the speaker or sell them speratly. if you break the lil white door plug things don't worry about it, though you need to go to the dealership and get a few as napa and the such don't carry ours.... they were only 1.50$ or something. and if you are going to be running new speaker wire i would suggest being careful of the stamped hole where the white plug is as it is sharp as hell and cut one of my wires, so i would pull out the plug then use a piece of duck tape to gaurd the edge of the hole so you don't have the same issue....
any more questions feel free to ask...