I am several hours into this method, and I will share some thoughts on where this project stands. Not to discourage you, as I do plan to proudly share some pictures when I complete this (and i WILL complete this).
1) Getting your new mesh to the correct shape is a challenge. Unlike the Grillcraft sheets (or similar), the ABS mesh has to fit almost perfectly, as snug as possible because of the thickness for it to sit properly into (not just on top of) what you cut out.
2) Attaching your new mesh to the frame is difficult to do cleanly. While it is very close to vertical, it does sit at a slight angle - adding another wrinkle to the thicker mesh fitting.
3) You will most likely want to also build a frame of some sort (see [MENTION=90395]Sundog7121[/MENTION]) to hide any blemishes around the edges and give it a stock look. I'm not sure if that's why Sundog did it, but it's why I'm doing it.
All that being said, I am by no means an expert at modding or fabbing, but I am relatively creative with a Dremel. I'm sure many T4R members could knock what I am doing out in a quarter of the time. I bought a replacement stock grill from a member so I could take my time getting this right and I still have my original if I don't like the result.