Converting toslink output to coax

I ran across a website describing how to mod an XBox AV Pack to install a coax digital output instead of a toslink output. Seemed pretty easy:

I've got a little MAudio Sonica I use, which is a USB to toslink converter for audio. I'd rather have a USB to coax digital converter, however. I'm thinking about cracking it open any trying this mod, but wanted to check with the tech heads to see if this is advisable... Is the only difference between toslink and coax an optical jack fixture v. a coax fixture? The MAudio internals probably don't look the same and may use a different toslink fixture. Is there anything I should look for in terms of knowing which leads to solder where? A double check to verify it works before hooking it up to expensive gear? If I hook it up wrong, how badly can I damage things?
I looked at the site you pointed to, and the idea seems interesting. BUT: They are guiding you to SPECIFIC points in the box to connect to. To assume you can find the correct spots in your Sonica... Hmmmm.
The wrong polarity... that is connecting them in reverse, could ruin the parts it is connecting. That is a 50%/50% chance. IF you could try it on a cheap item... to test it... I am guessing that the item on the output would NOT be harmed, but the item on the input could be, if the polarity is wrong. (this is just a guess)
And any solder-heads can flame me if I am wrong, no problem.
(The wires must be on the part of the unit that is taking the signal before it is converted to an optical signal) Anyway, good luck.
This is VERY interesting, and I bet a bunch of folks would like to do this to various CD players etc...
Is that actually that easy? The signal before the Toslink's curcuitry IS SPDIF???
Well, Audio-muffins??? ahh... Mavens??
(I would do it... if I had a clue...)
I asked about this at the audioasylum site in the tweaks forum and got some links to more complete discussions.
Try the audioasylum tweaks forum and look for my post's answer...
The most useful reference seemed to be:

"The signal at (used to drive) the toslink is the same signal as used for the coax out. So, find an old unit (Cd player) that has a coax out and remove it's tramsformer. Or you can use resistors to scale a 75 ohm output. The signal is TTL at around 5V, and the coax out is 1V. So scale resitors to give you 1V and use a 75 ohm output resistor. Good Luck, bobwire"

The really sad part is that a week ago, I finally threw out my old Micromega Leader 2 CD player. *argh* This happens every time I throw something out...