Is there another way besides taking off the dash to get to the a/c unit

 

unfortunately no, you'll have to remove the dash to get to the three bolts holding the cooling unit to the firewall. but removing the dash isn't terribly difficult, there are only 15 bolts and a few electrical connectors holding it in there, depending of course if everything is in good shape...but yeah, it's good practice..

 

I actually just finished doing this myself. There are bolts that you can only get to with the dash out. Removing the dash isn't too bad, just take you time and get hold. When you get frustrated and try to rush is when you break things.
That said, there's really no point in removing the cooling unit. The entire thing only weighs 6 or 7 pounds.