Right, I have just done this job, so I thought I would write a very quick guide for anyone that is interested. It took me an hour, but that was mainly because I kept running indoors to dodge rain showers. The job should probably take half an hour. These instructions are for the driver's door.
Small flat blade screw driver
10mm socket + suitable handle
T40 torx bit
4mm hex key
posidrive screw driver
First, CLOSE THE WINDOW, then open the door wide and check that you can get the T40 torx bit plus handle onto all 4 bolts which hold the door strap to the car body and the door. You will have slightly more access to those on the door when those on the body are removed, but not a lot. A big ratchet handle is unlikely to fit. Loosen these 4 bolts but do not remove just yet (mine weren't tight but I have heard that other people's have seized).
Look behind the door release lever and you will see a small black plastic plug. Lever this out and remove the screw behind it. Now remove the plastic surround from around the door release lever and unplug the connector from the tweeter (yes my car had a real one!)
Look inside the door grab handle (next to the window switches) and prise out the piece of rubber at the bottom. Remove the two 4mm allen bolts underneath it. Lift out the door switch console (pull on the right hand side first) and carefully unplug the connectors from the switches. Note carefully the order in which they connect as they are not all colour coded. If in doubt, take a pic. Remove the two 10mm nuts that are now visible inside the door (they are holding a metal bracket to the door).
Prise off the main speaker cover starting at the bottom. Don't put your screwdiver or fingers through the delicate speaker cone! Remove the 4 screws holding the speaker, lift the speaker away, disconnect the connector on the speaker and put the speaker somewhere safe. Then remove the 2 screws from behind the speaker.
Looking at the top left of the door trim, you will see a triangular piece of plastic trim immediately opposite the door mirror. Gently pull this off.
Starting at the bottom left of the main door trim, gently pull the trim away from the door. Work all around the bottom and both sides of the trim. Now gently unhitch the trim from the top by lifting it upwards. Do NOT damage the door membrane. There is NO NEED to remove this or slit it in any way.
Finish removing the 2 torx bolts holding the door strap to the car body, (noting how the closed part of the small hinge is facing the inside of the car). Now remove the other 2 torx bolts and prise the rubber boot off the door strap.
Now, carefully slide your hand through the hole where the speaker came out and reach up into the inside of the door. It is quite easy to reach the main part of the door strap. Pull the door strap out of the speaker hole. If you find that you cannot reach the door strap because a weird pane of glass is in the way, this will be because you failed to close the window as instructed earlier
Now reverse the procedure to reassemble, carefully noting the orientation of the door strap with the closed side of the hinge inwards. Before you push the door trim back on, remember to lift it over the rubbers at the top, make sure you pull all the door switch cables through the hole and make sure all the trim securing plastic posts line up with the holes before you thump the trim, otherwise you will bend the posts. Also make sure the door lock button (top right) is pushed through the hole in the trim.