Quoted from Mr_Tantrum:
By far the easiest way that I've found to move a pin upstairs with the least effort and in a safe manner (while leaving the backbox attached, but folded down) is to use a moving blanked or something similar. I've done this up curved stairs and stairs with a 90 and 180 degree landing half way up. You can do it with as few as 2 people (3 is better). Lay the blanket on the base of the stairs with extra at the top you can grab. Lean the pin (in or out of the box) onto the blanket (I do it where the long side is on the blanket - same orientation as when the pin is setup). Then have one or two people pull the blanket up the stairs when another stays on the down side to push and make sure the pin doesn't slide off. The idea is to slide the blanket up the stairs with the pin on it. I've only done this on carpeted stairs, but it is surprising easy compared to trying to do it with a dolly.
I've used the same technique going down carpeted stairs.