Just use a 12 volt power source on the connection on the round part, there are three tabs, one is left, one right and the middle I think is negative (dont quote me on that), When I did it I used sheilded aligator clips to work it out and no need at all for the hard ways, works a treat, the wheel alignment guy checked all my nuts and bolts as I left the rubber boots loose and he zipped tied them after.