Step 11: Use the ratchet and T45 bit to re-install the anchors.
Also inspect your corners to ensure they are lined up and not folded before securing all the anchors.
Step 12: Snap back the rear snap plate to the frame. Use the palms of your hands, no need to beat this part with a hammer.
Step 13: Finalize your inspection, your install should look like this.
Note: Left over cuts of the mat to be discarded.
Let me know if this helps you, so glad I contribute to the forum and the Hummer community.
-Algy