[quote name='Sugarphreak' timestamp='1300493131' post='25964']
He is talking about the plastic caps on the side of the box bed; seen here highlighted in red;
[/quote]
thx for the picture, dont remove the bed lining because the rail is held in place by fastener clip on's, here is the exploded view and instructions.
Pickup Box Side Upper Molding
Procedure
1.Begin lifting at the rear edge of the box panel molding.
2.Lift the pickup box side upper molding working forward to release the 22 integral retainers from the outer box panel.
3.Upon assembly of the new box side upper molding, align the four retainer pins to the box outer panel.
4.Working from front to rear apply downward pressure to the molding in order to secure the integral retainers to the outer box panel.
Hope it solved the mystery <img src='
http://www.canadianhummerclub.com/forum ... >/wink.gif' class='bbc_emoticon' alt=';)' />
Update on this subject
If you want to remove the rail under the cover you'll have to remove the side of the bed liner as follow:
1.Open and support the endgate.
2.Remove the pickup box liner - front. Refer to Pickup Box Liner Replacement - Front.
3.Lift the latches and remove both front cubby doors by lifting outward then upward from the pickup box side liner.
4.Lift the latches and remove both rear cubby doors by lifting outward then upward from the pickup box side liner.
5.Remove all four cargo tie down hooks. Refer to Cargo Tie Down Hook Replacement.
6.Remove the pickup box liner. Refer to Pickup Box Liner Replacement.
Side Retainer ( Qty: 8 )
Remove the four lower endgate cable bolts.
