Terminal To Boost VRAM

I upgraded my RAM on my mid-2012 MBP and now there are 2-3 GB of RAM lying around lazily at any given time. I want the GPU - which is capped at 1024 MB - to have access to 1 GB of that RAM (essentially, to have it reach from 1024 to 2048 MB of VRAM).

I followed the guide from here which has been a success to several other mid-2012 MBPs:

http://forums.macrumors.com/threads/hd4000-driver-hack-for-custom-vram-size.1573 528/

However, when I follow the directions and reboot, my GPU disappears and is replaced with "Screen 3 MB" for graphics. 3 MB as you can imagine is barely enough for the computer to display the screensaver, much less do any real work. This happened in at least one other documented case, and I am wondering if anyone here can tell me why it's happening.