Welcome to the world of Volvo window switch repair! I have repaired or replaced the switches on my wife's car about a dozen times. I pop off the fabric panel insert above the switch group. Then the 4 switch panel will come right out. WORD OF CAUTION, be careful removing the door panel insert, the plastic plugs that hold the fiber-board backed fabric insert to the door panel will pull out of the back of the fiberboard core if you get in too big a hurry (I know from experience).

The switches are held in with retainer ears in the 4 switch panel. You can carefully spread open the retainers with a very small flat screw driver or knife blade and ease the switches out. BE CAREFUL because the thin plastic clips are fragile and will break if you pry too hard (again, I know from personal experience and it is pain to then keep them in after reinstalling the switch panel in the door).

Because I am so cheap, and love working on the wife's brick, I disassemble the switches and clean/polish the contacts (they carbon up over time) with the end of a pencil eraser or small jewelers file (Harbor Freight). I reapply an electrical contact grease and reassmeble the switch. Juggling the leaf switches and the little detent balls takes getting used to (grease holds them together), but after a half dozen times, its second nature and you can do this in five minutes ;>

Good Luck,
escrivner
1985 740 GLE 216,000 miles