When I had to change the heater core on the truck, the whole dash had to come off which was a pain in the a**
BUT with time, it's really not that hard to remove and swap it out. I'm sure I used a forum here a couple of years ago about following instructions on removing the whole dash. It's just a couple of bolts.
I have the tan interior. Trust me, the extra work to convert it to the full tan interior is worth it.
This is what I used:
Heater core removal