Look here
http://986forum.com/forums/performance-technical-chat/37984-winter-project.html
You don't need to be worry about the air bag, it doesnt explode by itself.
Worst case you get a fault code.
To prevent that, just disconnect the battery, and wait 15 minute before removing the door panel. By that time, the capasitor that backs up the air bag system, will be discharged.
Removing the door panel cover is relatively easy, but you will need torx,Allen,and philips screwdrivers ( go figure).
You can find very good instructions for rmoving the door panel, on the pelican parts website.
Just one tip. Make sure the window is up before you disconnect the bettery.
If not, it will block your access to the door lock mechanism.
Good luck.