What problem you having on this bit? have you kept it as a .zip and put it on the root of your goldcard?
heres steps i followed
4. Run Test RUU Installation
Turn your phone off and insert the GoldCard microsd card into the phone.
Turn the phone on and connect it to your PC (harddrive mode).
Move the rootedupdate.zip download onto the sdcard now in the phone.
Turn off your phone, and unplug it from your PC
Turn it on again while holding the back button.
You will see FASTBOOT on the screen in a red box.
Connect the phone to your Windows PC and run the textruu.exe you downloaded earlier.
Once the update is complete, your phone will enter the default configuration wizard. Turn your phone of right away at this point.
With the phone turned off, unplug it from your PC.