What I do to go down the stairs is pretty much the opposite of what my teacher showed me about going up. One person takes their right hand and puts it in one of the holes on the back of the harp, and then wraps their right arm up and over the upper part of the neck. Then, tilt the harp backward (as if you’re going to play) and put the left hand further down the neck to keep it steady. Then, the other person reaches down from the bottom, similar to going up the stairs. But yes, the tuning pins can dig into the skin, so I usually try and have a jacket or long sleeves to lessen the effect.
My biggest problem is keeping the harp from tilting: that is why I asked the advice of my teacher.
I have yet to try going up with this new method, so I hope there aren’t too many problems with steadiness….