I have not adjusted mine, but I've had a similar setup before and adjusted them to level my FW when towed on my higher 4x4 truck. To adjust you jack all the wheels on one side and pull them. Then you remove the bolts holding the spring to the frame and reposition them at the height you desire. There are several choices. On my last setup the bolts had shoulders to stop you from crushing the frame and the hardest part of the job was getting the shoulder to line up again when re-inserting the bolt. Over all, heavy work, but not at all difficult.