Combination of knife and fabric scissors. It was no fun...I'm sure there's a better way I just don't know what it is!Your hard work is paying off and it's all looking really good. I am curious how you cut the dimmer switch hole? I lost my grommet (purchased the carpet probably 8 months ago and somehow in the process misplaced the grommet) so had to order another one yesterday. Was contemplating how to cut the hole and thinking it was going to be a pain in the neck. Part of me wishes I had ordered 80/20 loop as the ACC thick cut pile I bought is way harder to tuck under things like the kick panels, etc.