On some model Silverado trucks the backup camera mounting location needs to be modified to accept the new camera included in the upgrade.
If attempting to install the new camera into the tailgate handle, and you run into an issue where the camera doesn't sit flush onto the mounting location where the 2 torx screws attach, than you will need to trim the raised edge next to one of the torx screw locations (see attached photo, illustrated in red is the edge requiring trimming).
once the edge has been cut with either a small flush cutter, razor knife, Dremel etc... the camera will mount flush and you can proceed with the installation per the Youtube video.