I also have a new 377RLBH. You need to be fairly level across the axle for this to work, so you still may need to have linx-levelers or similar under one side or the other.
1) Chock wheels
2) Get blocks under all six, lower the fronts by pulling the manual pins to get them close to the blocks.
4) If you are "nose high" leave enough space so that toy can get the nose down to level after you get the hitch pin disconnected.
5) Raise nose by lowering front jacks manually, until nose lifts enough that you see daylight between hitch plates.
6) Make SURE that wheels are chocked!
7) disconnect trailer plug wire and emergency brake cable from TV
8) Double check chocks!!!! (Yes, I'm OCD about this!)
9) Make sure tailgate is down.
10) Pull TV out from under nose.
11) Push "auto level" button on control panel, open a beverage, and let it do it's thing! It adjusts fronts first, then rears, then tweeks side to side as necessary, then it puts the center stabilizers down.
12) If any of the jacks bottoms out before it makes contact with the pads, and doesn't provide stabilization, you get an error message. Manually raise this jacks, make your pad taller, then restart auto-level.
The DVD has some great info on it regarding troubleshooting and adjusting.
Good luck with it! It took me a while to get familiar with it. My biggest problem was that I thought that it was like a motorhome and lifted and adjusted left to right. It doesn't. That still needs to be close, using linx-levelers or boards.