The head should be down and ratchet-strapped to the cabinet boddy with padding between the head and the glass.
Legs off
Ratchet-strap the game to the dolly with the bottom of the game snug against the dolly frame. DON'T skip this step.
One of you is on the dolly handles, and the other is below, providing some back pressure as you go down one single step at a time, stopping on each step
Let the wheels roll over the edge of each step and then down to the next; don't let it "thump" down
Maintain control
Let the dolly take the weight, not your backs. The entire weight of the game is on the wheels and axle of the dolly, balanced there
Keep the wheels against the step, and do NOT pull the bottom edge of the game off of the dolly foot.
Go one step at a time; don't rush
RM