replacing evaporator coil and heat core

Yep already done it a bunch of times..
You will just want to take your time, the dash actually comes off quite easily, just the bolts up by the windshield, and then the ones near the floor on the passenger foot wells.
Once there your heater assembly is actually in open view. Just be careful, and be sure to have the battery disconnected. I took me less than 4 hours out and in with my dash.

I replaced my heater core without removing the dash. There are two screws at the back that are a pain, but it is able to be done. Took me about 45 minutes total. Not that hard.