Chevrolet 2005 SSR Pickup Owner's Manual page 101

Side Rail with End Cap Removed Shown
3. Insert a locking tab into the forward end of
each side rail and slide the tabs rearward.
Then reinstall the endcaps on the forward ends
of the side rails.
If your vehicle has an access slot on the forward
end of each side rail, insert the locking tab into
the access slot and slide the tabs rearward.
4. Loosen the knobs located on top of the telescoping
cross bar by turning them counterclockwise.
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