And there is a release button thing inside which you need to push in with something like a bent bit of clothes-hanger wire. If you just undo the screws you'll be pulling away at it all day but it won't come off!
It's a round black thing near the hinge on the fuel cap if I recall correctly.
After removing the 3 bolts and pushing in the catch, you need to pull up the assembly being careful not to damage the electrical release cable. Once lifted, remove the 2 screws that attach the release mechanism.