Help With ATH-m50 recable, Question about cable shield! Options

[tehprairiedog]

I have a question regarding recabling my Audio Techinica ATH-m50. Don't worry, I'm not trying to "hear the air between the guitar strings" or anything, heh. The cable has separated from the 3.5mm plug at the end. I saw some pictures (about halfway down http://www.head-fi.org/t/484744/crosstalk-...0#post_6601078) on recabling them and thought it looked like a fun project, but I want to try to do dual entry. I thought of drilling a hole in the right earcup and using Mogami W2534 qaud cable with a DIY y-split and terminating with a 1/4" TRS plug. Does this sound like an okay idea? So my questions are about the shielding. Is it okay that the wires won't have shielding between the headphones and the y-split, and should I connect the shield to the ground on the TRS plug? Some people say connect only one end of the shield, some say both ends, and the guy who started that head-fi thread said to not connect either end of the shield! I'm quite new to DIY, so I'm sorry if this is a stupid question, but I'm confused and haven't been able to find a very good answer through searching on Google. Any help would much appreciated!