I stay overnight at the Hilton fairly frequently, normally on a sub-$80 rate.

The thing about the tunnel is the confusing signage at (3) below..

My recommendation is:
(1) Take the elevator from near baggage claim down to the bottom floor. If you have a luggage cart, TAKE IT WITH YOU.
Depending on which elevator you take, you'll either need to take a right out of it, or go straight ahead, in both cases following signs to the Hilton, to reach
(2) The tunnel. If you had to turn right out of the elevator, you'll need to turn left into the tunnel. If you came straight ahead, there's the tunnel in front of you. There are moving walkways. Do not try to take your luggage cart on them.
(3) Here's the confusing bit. Part way along the tunnel, where the moving walkways end, there are TWO signs pointing to the Hilton, one indicating turn right, the other indicating go straight on. TURN RIGHT.
(4) Follow this tunnel up a short ramp and you'll come to elevators on the left which will take you to the lobby level.
(5) On exiting the elevator, take a left and the check-in desk is right there, a few feet away on your right. Park your cart by the desk and check in.
(6) Return to same elevators with your cart. Alternatively, go to the other bank of elevators (closer to Andiamo restaurant) if your room is at that end of the floor (the check-in agent will tell you which end you are).
(7) Enter elevator with your cart and proceed to your floor. Then proceed to your room.
(8) Enter room, still with your cart. There is normally room to park it near the window. If your cases stick out a long way on either side of the cart, you may have to offload them before parking the cart near the window, otherwise getting past the bed(s) may be difficult.
Finally,
(9) When leaving the room to return to the airport, reverse the process, and YOU STILL HAVE YOUR LUGGAGE CART to help you!