96 AC Evaporator Leak?

I'm told I may have a leak under my dash in the AC Evaporator? In 1 and a half weeks I lost the fresh 2lbs of AC coolant and dye I just had put in. The Dye does not show up anywhere in the engine compartment. Does anyone have any experiance replacing the evaporator or tearing apart that section of the lower passenger side dash??? Its starting to get warm here in Michigan!!