I found that the easiest way to get at the speakers is to remove the door from the car by unbolting the hinges.
You can further facilitate door removal by cutting the wiring harness (don't worry, you won't need it again) with something sharp, but not so sharp that it will leave a clean wound should you slip and gore yourself.
Then get a flamable liquid and pour it into the plastic mesh grill. Ignite your flamable liquid and wait for the interior piece to burn away.
Your speakers are now ready for R&R. The burned smell will go away once your doors are replaced with new ones, and the wiring harness will never come back unless you keep thinking about it.
Glad I could help!
