Today we have a video of the full replacement process for a heater core on a 2007 GMC Sierra classic body style. The procedure is the same for many other GM trucks:
9907 Chevrolet Silverado classic body style
9906 GMC Yukon and Yukon XL
9906 Cadillac Escalade (EXT, EVS)
9906 Chevrolet Tahoe and Suburban
9906 Chevrolet Avalanche
0307 Hummer H2 (dash and firewall are a little different but the heater box is the same.)
It is easier than it looks, the dash has to come out, but it comes out as an assembly and only needs to be pulled back, not totally removed.

My website if you want to purchase a car or parts: www.vehcor.com

Amazon store: https://www.amazon.com/shop/vehcor

For Vehcor merch: https://teespring.com/stores/vehcor3

#boringbuildfriday #heater