I had trouble with the rivit nuts spinning as I tried to install... so I drilled little holes in flange and inserted two finish nails to prevent spinning. I used a cable lug as a tool to hold everything in place. After the fact, and after asking around on www.diyelectriccar.com/forums it sounds like it would probably be easier to thread an extra nut on a 2" bolt and 'untighten' the nut while holting the thru bolt to install the rivit nut. I was already done, so did not test to see if this works better.