Don't cut anything. You can buy these long thin crimp-on metal pieces in the electrical section at Pep-Boys. Crimp them on the end of each wire and cover the connection with electrical tape. The ends fit snugly into each hole of the stock recepticle plug. This makes it easy to take off if you change your mind and want to replace them some day.
I have lost the packaging for these parts but I'll try to look for them the next time I'm at Pep Boys to see what the part numbers are. They are meant for replacing the contacts inside some kinds of stock electrical plugs.
PSM WRX Sedan
HKS MBC, Forge BOV, Defi gauge pod, Cusco sway bars, Kartboy droplinks, STI v2 front lip, stainless brake lines, STI foglight covers, Duffgaurd Diff protector