vents on rear cab
Just ch anged mine in 15 minutes without pulling bed. The old one was removed by cutting of the back of the plastic vent with a dremel and then pulling remaining vent into cab and discarding
On the new one (also plastic) notice there is a square flange portion with rubber seal to be external of the cab., I used a dremel tool to cut the u-shaped lip off of the external square flange. On the portion to be internal of cab notice a trough running the length of the bottom edge. I cut this trough off being careful not to harm any of the clips.
The vent is now thin enough to slide through cab hole, short end first, downwardly. When vent is between the cab and bed rotate 90 degrees into position and pull the *** end back into cab until all four clips click/lock.
I plan to gorilla glue the trough back onto the vent but testing with garden hose indicates that the trough is not needed... so up to you whether or not to glue trough back on.
If you screw up and cut too much off no biggie...plastic glues well... and new vent is only $15 from dealer. For my 2008 f350 crew cab part number for vent (called a grille-air inlet) was 3c3z-54280b62-ba.
Beats the hell out of pulling bed.