I'm having the fun and joy right now replacing mine got the entire dash removed ( you have to take everything off except for the steering wheel) just to get at it... I'm havin a blast... well decided to take a little break and grab some lunch just wonderin if anyone has done it.. oops and by the way i realized i used the wrong there, i mean theirs yet.

 

Ive done it on my mustang it it wasn't fun either. Had to take off the whole dash too. PITA. Ive seen on a forum where one had to be done for a nissan titan taht $hit looked crazy. Good luck with the job. Remember to double check it before you put everything back together, b/c you dont want to have to take it back out!!!!
Heres some pics from the titan heater core:http://www.nostreetracing.org/forums...an+heater+core