if ive got the right truck in my head then the two top speaker grilles pop off and there are 4x6 there and then there are 2 4x6 in the rear. those are a royal pain in the ass to get out. pull out the center piece of plastic across the back. then unbolt seat belts, pull out a few more screws, take off the upper cross plastice and they are in the "b" pillars. if it were me id snag some nice fronts , disconnect the backs and put a new radio and sub in.