Purchase a Purolator cabin filter for your truck, it comes with complete instructions.
The 2006 GMC Sierra 3500 SLE with the LBZ 6.6 Duramax does not have a cabin filter.
they do not have a cabin air filter
These trucks do not have a cabin air filter.
The cabin air filter on a 2005 GMC Sierra is changed by removing the cover under the glove compartment and opening the filter housing. The old filter is then removed and a new filter put in its place.
Under the dash on the passenger side.
Remove the glove box door. The cabin filter is in a holder on the left side of the heater core.
They don't have one
Purchase a Purolator filter. It comes with complete instructions.
The cabin air filters are located in the heater box above the lower panel, mounted below the glove box.drop the plastic panel, 3-7mm screws, then you will see a black access panel, with 1 screw holding it up. the 2 filters are located there. Sorry, I misread the question and read it as 2000 GMC Sierra. Your 2008 GMC Sierra doe not have a cabin filter.
How to Replace a Cabin Air Filter on a 2006 GMC
There is no filter on a 2003 yukon, GM stopped inside filters in 2002