2008 Chevrolet Avalanche Owner's Manual - Page 164

To remove each drain grate, do the following: 1. Remove the cargo panels or tonneau cover. See Cargo Cover Panels on page 2-73 or Tonneau Cover on page 2-91 for more information. To replace the drain grate do the following: 1. Line up the clips on the vehicle with the slots in the grate. 2. Grasp the edges of the grate and pull it out from the vehicle. Flush the drain with clean water. 2. When you are sure that the clips are aligned with the slots, push the grate down firmly. The grate should clip into place. Do not force the grate if it will not clip into place; realign the clips with the holes and try again. 2-88