You can find some great details provided by my bud Thurston on the link below. You can probably PM him, nice guy, even if he needs a shave (see his avatar). He can probably give you links to other posts with further information on where to buy materials. There will be no improvements in SQ, unless you really want to believe in it. By keeping separate ground wires all the way to the plug you will avoid loss of separation by using an extension cable. Like I said, if your cans are high impedance this is not such a big deal.
Thanks, my cans are low impedance (NAD HP50s) so that is a small concern. I will be hopefully finding somebody willing to do the work as I don't mind paying for it. I don't own any soldering equipment and frankly with how nuts my life is, even a modest project isn't for me right now. Thanks again.