It appears the wheels that run on the track of my (14 year old) Minivator 1000 stair lift are worn and it now tips & feels as if I may slide off! I have an alternative seat unit which could be fitted but the manual indicates that a "feeder track" and a "driver seat toggle loom" are required. presumably to get the old one off and new one on? I rather suspect that getting the old one off would be possible without but can't risk ruining either track or seat. any suggestions?