asus g53sx fix / mod help

I modded my Asus G53SX in an odd fashion. I cut a hole to the right of the power jack and inserted a new and better jack than the stock one that broke on me. But in order for the new jack too receive power I soldered the inner wire of an old power cord to the correct places. But this was only a temp fix since the wire is so bulky. What is a recommended type of wire to use? And unrelating to the wire, is there anything I need to know about replacing the motherboard? Like on removing the processor and replacing it in a new motherboard?