I modded my xbox 1 with no soldering experience. I bought a soldering iron and spent an afternoon soldering on an older mother board... next day I cracked open my xbox and soldered several pins and one wire to install the mod chip... This was fairly tough soldering since The wire had to be soldered into a SUPER TINY hole without getting excess solder on the motherboard.
Soldering two wires together is a piece of cake though. Just clean the wires with an alcohol swab first b/c solder does not like grease/grime/ect.
Anyway, supporting Hutzal's Idea I would just use a keyhole saw like this to cut the hole:
http://www.lowes.com/lowes/lkn?action=productDetail&productId=90294-51834-8052&lpage=none
