I rented the smallest uhaul trailer I could find (looked kind of silly behind my F350), which had a ramp.
The store loaded it with a forklift, and I had them leave it as close to the back of the trailer as possible.
I was able to slide it down the ramp by myself (asking my pregnant wife for help was obviously not an option!). I'm not a big guy, just moved it slowly a little at a time. If I had to do it again, I would get one more person to help, just to be safe. But it is possible to unload yourself. Just go slow and be careful.
As you can see, the trailer was at an angle anyway, which helped. If necessary, you might be able to (carefully) unhitch the trailer and lift the tongue. Of course, that could get you too steep an angle

, depends on the trailer.