Not very helpful but...
Plumber was doing our bathroom and was there for a few days. I would be playing, sorry working, on me bikes in the garage, I had a small 125 SM style bike I had used to get my bike legs back some years ago. I wanted to get rid of it but had not done anything about it. I mentioned this to the guy in passing, he said that he was interested. So a deal was struck and a discount on the work he was doing obtained.
So to get it in his van we put a plank of wood up the back of the van onto the bumper I started the bike up and pushed it up the ramp till it got to the bumper and then used the engine power to get over the step while he dragged it in from the van and lent it against his stuff.
So a plank of wood and brute force then.