91 S-10 heater core replacement- any hints?

I started to replace the heater core on my 4.3 L, no A/C, S-10 and have now realized it may be more work than I first thought. I managed to remove all the bolts that held the plastic cover and move the cover a couple of inches so I can see the heater core but I can't get the cover totally out. I would guess the next step is to remove the dash to give myself the few inches I need to get the cover out. Do I have to remove the dash or should I try to force the cover? If I have to remove the dash is there any tricks? Thanks Andre