Assuming it is a trailer with 2 ramps, either borrow a third one, or else drive up to the trailer at a 90 degree angle (rear wheels next to end of ramps). When the rear wheel lines up with the ramp, cut the steering wheel all the way while riding the brake. The front wheels will go up the other ramp, and be right at the edge just as they hit the trailer. Keep on swinging around till you are straight, and then just drive on. One word of caution doing this, if you do not cut the wheels and ride the brakes hard enough at the same time, it may tend to push the ramps off the side of the trailer. As a safety precaution, I have welded a couple pieces of angle at the end of the ramp brackets to keep them from sliding off the end of angle brackets. Of course, this only works loading nose first, not backing on.