I just did mine (97 F-150) this week with Don's instructions posted on this forum. I installed a NAPA unit ($45.00). Took me 5.5 hours with a friend helping on the actual moving if the dash. I did not completely remove the dash, just pulled it back and set it down an a small footstool on the passenger side. I took some pics of the dash and behind with it pulled back. I bought the hose disconnect tool at costplustools.com for $26.95 and picked it up at their local distributor's warehouse. I'd let it go for $20 plus shipping. I's a simple tool that you reach back in there and twist to release the tabs with. Do a Google for "Ford heater disconnect tool". Post a reply with your e-mail if you want to see the pictures of the crime scene.

Edit:
Here's the link to the tool.
http://www.costplustools.com/store-products-Radiator--Cooling-Radiator---Cooling-SystemTools-SCH93440-Schley-Chrysler--Ford-Heater-Hose-Disconnect-Tool_39249.html