If you do a search for this there are plenty of threads on it. The biggest problem you're going to have is that the mounts on the dash speakers are difference from every other 4" speaker, so you're going to have to do something custom to make new speakers fit.
If you're speakers are dead then, I would just cut up the speakers you have and use the mounts on a different 4" speaker. Also, when you remove the screws the speaker grill, and speaker just lift out, and then you disconnect the wires, I believe there is a plug.
Just search here and on RennTech, and you'll get plenty of information on this.
