Did mine nearly the same way. I wrapped the winch strap around the forward-most roller and then re-attached it to the bow eye. Using that roller as a pulley, I was able to crank the winch and pull the boat backwards on the trailer. I cranked the trailer jack all the way down, lifting up the back end, and made some sawhorses that slid just underneath the boat. When I cranked the jack back up, the trailer pivoted down, and the stern of the boat rested on the sawhorse. I then used the winch, but I wasn't moving the boat, I was pulling the trailer out from underneath it. When I got a decent distance away from the rear sawhorse, I slid the front sawhorse underneath, and pulled the trailer out. Fun job!