I have a F150 XL 4x4 and am replaceing the Heater core. Now wwith the dash in the front seat, I cut the aluminum lines through the fire wall and got the old bad core out. Now I cant get the new good core back in . No Videos anywhere. Do you have to break the A/C system down ??? 08 and before, and 2011 and beyond are covered. Mine looks NOTHING like either.