How do you remove the door panel to replace the door speaker on a 1986 Jaguar XJ6 Vanden Plas?

For the front doors, remove the inner door skins (grab the bottom and pull gently.) You can probably get away with just pulling the bottom loose enough to reach the screws around the speaker box. There are 3 or 4 screws holding the speaker box in. Remove the screws and unhook the old speaker. Pull the box out from under the door skin. There are 4 nuts holding the speaker to the inside of the box. Remove those (it's tight so you may want to use a needle nose pliers.) and the speaker is free. The rear speakers are a little easier. The box is contained in the armrest. This is held on by a couple of screws on the bottom. Remove these screws and lift the arm rest free. The speaker is contained in a box similar to the front.