Head down to your local Auto Supply house and ask to see the Lisle Catalogue...they make a great door panel tool that is bent in a U shape at the end so you can slide it under the panel from the inside and still lever the panel away...

Volvo door panels are held on with the usual button style fastner, like ford and the rest...but you also need to remove the arm rest (2 small plugs in the armrest hide the phillips screws) and the door lock knob if equipped and the plastic surround for the door open lever...if its a wagon flip the rear seat bottom up and leaver the rear seat back in vertical position...this will give you access to the bottom edge without major gymnastics..

if its a Power door/window deal once you get the door open check the wires going into the rubber accordion type tube that is between the door jamb and the door on the hinge side, the wires can and do get futzed as the Bosch wiring was known to degrade in place and short out ...also the power window switches are known to get corroded and gummy...RS Tuner Cleaner helps here..

If the window cranks are frozen try CRC or PB Blaster and let it sit for a while...2 or 3 days of soaking may free up the mechanism but a salvage yard replacement may be in order and mucho cheaper than new... also check to see if the lower drain holes are clear and general look see while you are inside but expect the door panel composite cardboardium/wood pulp to probably be flimsy and rotted from the water that froze up the window cranks...

The plastic fastners that hold the panel in place doo break and cost $1 each,,,buy a set of 25 or so and replace 'em all so they don't FUBAR you in the future...also if the paper/plastic water sheld is shot make a new one out of 3 mil poly and use latex caulk to hold it n place (the cheapo Home Depot black exterior crap works great!)

Stoney