Does anyone have a easy way to move pins up and down stairs that has a platform half way up?

My basement stairs are just wide enough to move a pin up and down. The doorway is 29 1/2 inches. The stairs are a little wider. But, the real issue is that half way up, there is a platform that makes a right hand turn. There really isn't enough room to turn the machine on a hand truck on the platform. Is there any tricks to do this?

My first pin, I had them move the hand truck to the side of the pin on the platform.

My second pin, they turned it on the platform, but I thought they were going to lose a nut!