I never used them in index mode. I completely disassembled them, then mounted them piece by piece, starting with the clamp, then the next piece that has the stop for the cable housing. It can go in any of six positions, as I recall, but depending where you put the clamp it will be pretty obvious which position you need to use. Once you put the cable housing and that stop in place and the cable housing, then everything else is pretty obvious.

I am under no delusion that I set mine up "correctly," but they worked very nicely.