GMC 2001 C3 Owner's Manual page 125

3. Remove the three bows by gently pushing them
-
against the spring loaded end. The three bows are
labeled front, center, rear to remind you of the order
in which to reinstall them.
To clean the tonneau cover, use mild soap and water.
If necessary, use a soft bristle brush to remove dirt
trapped in the grain of the material.
4. To add cargo to the box,
remove all bows and
the back rail and stow
them safely.
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