4 screws mate, one at the front and one at the back of the door. There's 2 more under 2 rubber grommets under the door card, make sure you have a magnetic screwdriver, cos if you drop them, it's door card off time! Once you remoce the screw, the door blade just slides backward by an ince or so and pulls off!
I highly recommend you get some new screw from Audi, they are 26p each(they was 6 years ago!) I think?