Drop landing gear..drop air in bags..flip the 5th wheel switch check the clearance between mudflap brackets to the landing gear if your sliding forward don't go more than a third of the front axle and your steer weight is 600 lb per inch of treadwith per tire
You'll need to get a gap between your fifth wheel and trailer..any weight on the fifth wheel and you'll have problems.
Lubricate the pins with soap and water.
Slowly rock the truck after releasing the pins..should unlock just like the tandem.
Doesn't take much to move it a few inches.