I bought a camper trailer a few months ago, and I'm slowly starting to fix it up.

A friend towed it to my yard, because my vehicle is too small to tow it, but after he left, I realized it was too far back -- so I made a pulley system to move it using a technique I learned in Search and Rescue, and two pulleys I inherited from my Grandfather. The rope is anchored to the post, and the rope goes through two pulleys in a Z-shape.

It took a bit of trial and error since I was using things around my house and didn't have proper rope. At first I was using clothesline, which was terrible. It was too skinny for the pulleys and kept jumping out of the track and getting stuck.

The next day I borrowed some rope from a friend and got it working. 

But I still found it hard on my hands to pull the rope, so I threaded the end through a piece of old bed frame and used it as a lever.

Here is a diagram: