I had to replace the driver's side switch assy on my '98 S-70. If they are the same, the whole switch assembly just pops out of the door panel straight up. Then reach underneath and unpug the connectors. I didn't know this of course, and removed the door panel, breaking the door handle escutcheon, but I was able to glue it back together. That's when I saw that the whole assembly just snaps into the door panel. So for the pasenger side you would be removing the whole black section,the part that's the same size as the whole driver's side assy, not just the switch. I broke one of the switches trying to remove it, again not knowing what I was doing, but I figured it was bad anyway so I didn't have anything to lose. Good luck.
Bob