Driver's door stuck shut, 88 90Q

[Radek]

Hello everyone!  Thank you for your support in the past.  My 88 90Q is now
running but the driver's door cannot be opened anymore.  I bought the car
with the locks inoperational but found a crushed vacum line in the trunk and
fixed it.  After that, I could lock and unlock the car from the passenger
side (not from the driver side).   Tonight, the driver's door wouldn't open
at all.   First, how can I open the door, to be able to remove the inside
panel and get to the lock mechanism and fix or replace it?  Second, what are
the likely causes of this malfunction?  The other doors and the trunk are
operational.
TIA.
Radek.