You don't have to undo those screws - if you have a Bentley Manual see page 411-3
Remove the 3 screws at the top (inside ashtray, behing door lever and in the handle) then, you pry loose the clips all aroud and then, pulling the top of the panel away from the door, lift up. The center of the panel is held in a clip that will slip free as the panel is lifted vertically.
Sounds like the cable connecting the interior lever to the catch may be borken - they are inexpensive parts but a pain to replace because the end that connects to the latch is in a pretty tight place.
Good luck.
1995 530iA - 295,000 miles
1988 325i convertible - 180,000 miles