You can only change the official OEM label ratings by hiring someone/company to re-certify & make the modifications they spell out in their certification paperwork, but that may cost more than just going out and purchasing a bigger vehicle.
You can also add/modify everything up to the AAM's 11000 GAWR, but the 'official OEM rating still stands'
Best to go out and actually weigh your TV axle by axle fully loaded as if going to tow.
Then subtract that from the OEM listed GCWR and that will be the OEM's official MTWR for your TV. Most are extremely surprised that their vehicle weighs more than the door labeled TV weight.
Then deal with the expected PIN weight vs your ACTUAL remaining TV rear axle payload .
