You can buy some relatively cheap cable making supplies. You should start by making yourself a 3.5mm male to 3.5mm male patch cable. Once you get one of those working it will be a piece of cake to put a new plug on your headphone cable.
Need:
Soldering Iron
solder
Strippers
Side Cutters
3.5mm male plugs
Some fairly cheap cable(like canare mini quad)
and a multi meter.
If you feel comfortable soldering you can porbably skip making a patch cable, but it's good practice, and if you can build one then a headphone cable is no problem. Just gives a little more secure feeling cutting of the cable on your headphones. You could probably buy this stuff for under $100 easily.