If you drill out the rivets you still have a chance of reinstalling the stockers. you jsut have to work out how you can install them again. what i did was i drilled out the rivets for the back, took the whole assembly out and made a wooden copy to mount my aftermarket speakers. the rears speakers and the mounting bracket are basically 1 piece and its too hard to seperate them without doing damage so you're better off just removing the whole thing and making your own bracket as i did. As for the fronts you can unscrew the speakers from the bracket and pull them off. Give them a mighty tug as they are silconed on. you can then mount your aftermarket onto the stock bracket, i was only able to use 2 screws as the stockers are 4 screws where my aftermarkets are 6 screws. Ive heard of others drilling their own screw holes but i just added some silcone to help hold it on. it wont be going anywhere. alternatively you can do the same as the back and just remove the whole bracket by drilling out the rivets and make it out of wood again. some say you get better response out of a wooden mount.