Yes take the back cover off and you'll need a #1 Phillips head screwdriver. Look at the jack and you should see 5 contacts. the two in the from are for the sheild, the next two are the two you need to short, and the one in the back is negative.
Its a little fuzy but you get the idea. Or you could get a new jack from mouser for around 5 bucks after shipping.
Its a little fuzy but you get the idea. Or you could get a new jack from mouser for around 5 bucks after shipping.