Help with a GAF Anscovision Projector?

Hi,
I was just given a GAF Anscovision 688 because the previous owner thinks
I'm handy (at least more so than her). The reels seem to be turning,
and I don't see any obvious problems except the light bulb is dead. Can
anyone with experience on these projectors give me a hint about how to
access the light bulb--maybe there are screws involved? I can pop the
plastic caps for the the large (full case size) mechanical area and the
small film intake area, but it doesn't seem like the plastic cap
covering the light bulb/lens area wants to pop off--maybe it is just
jammed, but I don't want to force it if that's the wrong thing to do...
I'm more of a computer guy, so this is terra incognita--any help would
be much appreciated. Thanks!
Pizzapie