Pontiac GTO 2004-2006 - need help with a custom exhaust on 04!!

ok first of all i have on 04 goat. i want a split dual exhaust setup with an outlet on each side of the rear bumper. i've decided on spintech mufflers. first off how do i cut the bumper on the other side for the exhaust tip. also spintech makes a catback exhaust for the 04 gto with an outlet on either side of the bumper like i want. would i be able to weld my own tips onto this system or should i get the mufflers and do custom piping? i saw these tips called banshee tips im gona use too they look sweet, idk if any of you have seen them. any input or help is appreciated

www.pfyc.com has the inserts. I would go with the borla as it comes with sweet dual tips on either side as well as a hanger that bolts right up in a stock hole location on the passenger side. (no welding required) I used an air saw to cut mine and it was not to hard. They have a template for you to use with the banshee inserts, wont take long at all.

inserts for cutting bumper? im not sure what you mean. i like the borla but i want the louder sound of the spintech but thanks for the advice