You need to get inside the door:
Gently prize off the plastic covers around the wing mirror lever and the rear door pillar/lock button. Held on with plastic push clips. Also the speaker cover just unclips.
Unscrew the door handle, door pull/tray, speaker and four screws at the bottom of the door panel.
Remove the window winder, just pulls off.
Pull the door panel off, slowly and consistently, it's also stuck on with blutack stuff.
Pull and lift the door panel off the window runner and it should come off.
Remove the two screws on the rear of the door by the lock, two to the outside to release some plastic security cover.
The barrell can be removed/replaced by turning a white plastic collar which is keyed onto the barrel. Anti clockwise to get it off.
Shove it all back in reverse, putting as much of the blutack back in place as poss.
Put plasters on the cuts you get!
Kevin, January 2007