I performed this modification over the course of 3 afternoons. Found a 2004 SLK320 track on eBay last winter for 125.00, offered him 75.00 plus 38.00 shipping and he took it. The instructions and pictures were very very helpful. I went slow, paid attention to the details, took pictures and because of the heads up on the push pin I did not break it. Before I started I hooked up my battery charger to the replacement track to make sure the 3 motors worked in both directions. I also lubed the gears and tracks before final installation. The step which gave me the most trouble was the removal and reinstalling of the power seat switch assembly. The assembly just did not want to come off or go back on easily and of course, I didn't want to break the assembly with too much force. Probably spent an hour on that step. Happy with the end result of 8-way power passenger seat. Thanks again for the instructions.