They litterally "layover" the exisitin gauge cluster. All you need to do, is pull off gauge needles, throw the overlay on, and replace needles. Make sure to put needles in same positions as removed. Also, be sure to check before installation to make sure gauge needles dont stick with the overlay on. Sometimes they like to stick, I guess the overlay just gets in the way. Either way,theyre pretty cool I guess. Not my taste, but my buddy did one that had nice BRIGHT blue and red lighting and it looked okay.