A few years back we had 3 active phone lines but only have 2 now. The 3rd line was only active in summer months and was connected to garage apartment. I would like to re-connect the phone jack in the aparment to one of the 2 active phone lines. I have loacted the NID and lots of wires in the basement. I think I have identified the wires from the phone jack in the garage ... how do I connect these to the existing phone line?