Yes they come with instructions on how to fit the dials, you need a little super glue aswell to keep them in place. but as for wiring it just says connect to a live, it doesnt give you a clue if you can use your original dimmer switch or to use a big chunky live or if a little weedy live will do. The one I used was quite thin but so was the cig lightrer wiring which was my other choice. If you use the cig lighter wiring it doesnt work with the original dimmer switch though and then you have to use the switch that came with them
Oh, when you finally get everything in dont touch the back of the switch that comes with the dials because when you touch the bare soldered joints and flick the switch you get a nasty shock, I know it's only 12v but for some reason it smarts.