Thule has an adapter that allows the Big Mouth 599 to fit on larger crossbars like you have with the # XADAPT2 which would be just what you'd need. view full answer...
You will need a Philips head screw driver to remove the screws holding the top cover of your Lippert Electric Trailer Jack with Footplate - A-Frame - 18" Lift - 3,500 lbs - Black # LC285318 on, but there are actually 4 screws. 2 in the front, 2 in the back, and 2 underneath the cap on the top of the jack.
I included a video of the # LC285318 for you to take a look at. view full answer...