Originally Posted by Battery Guy

All four of my speakers were completely destroyed when I bought the car. At the time I did not think that was a big deal, but it turned out to be a pain in the *** to replace them. Standard 4” round speakers physically fit, but there is no easy way to attach them to the speaker grills which are what actually holds the speakers to the car. My solution was to cut away the mounting pieces on the factory speakers, and use Gorilla Glue to attach them to the new speakers. While this sounds like a really bad idea, it actually works very well - almost a year later it is holding up fine. Crutchfield recommended making up some brackets from metal strips, which possibly could work as well.

In my case I had the base stereo, so no door speakers. My understanding is that the door speakers are much higher quality than the dash and rear speakers, which were absolute crap. So you may be fine leaving your door speakers in place - likely they are not blown. The dash and rear speakers use inexpensive paper cones, so it is really a matter of time before they go unfortunately.
Daryll