Help Modifying Kext and plist files

Hi
Ok I read a ton on modifying kext -but I jsut cant wrap my head around it.
My system is running great except for this.

my video card is working but only one display works.
Plus on my "about this MAC" under graphics hardware it reads this
ATI Radeon HD 4890:

Chipset Model: ATI Radeon HD 4890
Type: GPU
Bus: PCIe
Slot: Slot-1
PCIe Lane Width: x16
VRAM (Total): 4294965248 MB
Vendor: ATI (0x1002)
Device ID: 0x9460
Revision ID: 0x0000
ROM Revision: 113-B7710C-176
EFI Driver Version: 01.00.318
Displays:
DELL 2707WFP:
Resolution: 1920 x 1200 @ 60 Hz
Pixel Depth: 32-Bit Color (ARGB8888)
Main Display: Yes
Mirror: Off
Online: Yes
Rotation: Supported
Display Connector:
Status: No Display Connected


Notice my VRAM size -its way wrong -it should only read 2gb or 2048 mb -I believe this is why Im getting a -VRAM issue when installing Final Cut 7

My Device Id and Vender # are right --I looked those up. I have read a ton about entering the correct numbers in the ATI4800Controller.kext but I dont know how to do that and I have read and read and still dont understand.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>CFBundleDevelopmentRegion</key>
<string>English</string>
<key>CFBundleExecutable</key>
<string>ATI4800Controller</string>
<key>CFBundleGetInfoString</key>
<string>ATI4800Controller 1.6.6.25 (7429)</string>
<key>CFBundleIdentifier</key>
<string>com.apple.kext.ATI4800Controller</string>
<key>CFBundleInfoDictionaryVersion</key>
<string>6.0</string>
<key>CFBundleName</key>
<string>Radeon HD 4800 Controller</string>
<key>CFBundlePackageType</key>
<string>KEXT</string>
<key>CFBundleShortVersionString</key>
<string>1.6.6</string>
<key>CFBundleSignature</key>
<string>????</string>
<key>CFBundleVersion</key>
<string>6.0.6</string>
<key>IOKitPersonalities</key>
<dict>
<key>Controller</key>
<dict>
<key>CFBundleIdentifier</key>
<string>com.apple.kext.ATI4800Controller</string>
<key>IOClass</key>
<string>ATI4800Controller</string>
<key>IOMatchCategory</key>
<string>IOFramebuffer</string>
<key>IOName</key>
<string>ATI4800Controller</string>
<key>IOPCIMatch</key>
<string>0x94401002 0x944a1002 0x944c1002 0x944e1002 0x94411002 0x94431002 0x94601002</string>
<key>IOProbeScore</key>
<integer>65000</integer>
<key>IOProviderClass</key>
<string>IOPCIDevice</string>
</dict>
</dict>
<key>OSBundleCompatibleVersion</key>
<string>1.1.33</string>
<key>OSBundleLibraries</key>
<dict>
<key>com.apple.iokit.IOACPIFamily</key>
<string>1.2</string>
<key>com.apple.iokit.IOGraphicsFamily</key>
<string>1.3</string>
<key>com.apple.iokit.IOPCIFamily</key>
<string>1.2</string>
<key>com.apple.kext.ATISupport</key>
<string>1.1.33</string>
<key>com.apple.kpi.bsd</key>
<string>8.0.0</string>
<key>com.apple.kpi.iokit</key>
<string>8.0.0</string>
<key>com.apple.kpi.libkern</key>
<string>8.0.0</string>
<key>com.apple.kpi.mach</key>
<string>8.0.0</string>
</dict>
<key>OSBundleRequired</key>
<string>Safe Boot</string>
</dict>
</plist>

That is the ATI4800Controller.Kext
Where do I put in the info

Can anyone help me fix my problem.

thanks

Matt

PS this crad is the sapphire ATI Vapor X series 2gb ram
Asus Rampage Gene II Board.