There are two flashable zip packages. The first one roots the G2X. You simply flash it with Clockworkmod Recovery. The second zip unroots the phone for those who wish to unroot their device for whatever reason.
After rooting go to the Android Market and get the Busybox installer referenced below. Use that to install and keep Busybox updated.
Root Zip for G2X: http://www.mediafire.com/?92qpr525ztblh8w
Unroot Zip: http://www.mediafire.com/?2vr7cmgg7qcdn14
HOW TO ROOT
1. Install latest Clockworkmod Recovery using NVFlash, if you haven’t already done so.
2. Download the root zip package referenced above.
3. Put the zip package on your internal or external sd card on your G2X. Do not unzip the package.
4. Turn off phone and boot into Clockworkmod Recovery by pressing volume down and power and hold until the fancy LG (second one) appears.
5. Select install zip from sd card. Select and flash the root zip package. Note: You navigate in Clockwordmod Recovery by using the volume keys up and down and commit the action by pressing the power button.
6. Reboot your phone. You are now rooted.
NOTE: THE FOLLOWING BELOW IS OBSOLETE. IT IS LEFT FOR HISTORICAL PURPOSES ONLY.
Original post made on 9/9/11:
I wanted to run the stock Gingerbread ROM and wanted to root it without flashing a new ROM. I was able to succesfully do it and the instructions are below. I was attempting to make an update.zip to do this but it kept getting a "status 0" error. The original superuser zip by ChainDD also gets this error. So I decided to try and root it using ADB commands while running Clockworkmod Recovery. Here is how I did it. If someone can help me get an update.zip that will install without error in Clockworkmod Recovery to make this easier for people to install it would be much appreciated.
1. Download my G2X root package that includes necessary ADB files (Android SDK install not required) and unzip the contents. The package contains the latest versions of “su” and “Superuser.apk”.
http://www.mediafire.com/?6rdrdfxvdoq9nkv <download link for my root G2X package>
2. Install latest Clockworkmod Recovery using NVFlash, if you haven’t already done so.
3. Boot into Clockworkmod Recovery by holding down volume down and power until fancy LG logo shows (about ten to fifteen seconds). This is not the first one displayed when the phone powers up. Wait for recovery to start. Just to be safe perform a backup of your device’s current state.
4. Using the recovery menu scroll down to “mounts and storage,” press the power button, scroll down to “mount system” and press the power button.
5. Now that your system is mounted plug your phone into your computer (let drivers install if you have not done before – requires LG USB driver package).
http://bit.ly/qyoAxY <shortened link for direct download from LG server>
6. Open a command prompt windows on your computer. In the command prompt window change to the directory to where you unzipped the G2X root package.
7. Issue the following ADB commands. Do not type the the text in the brackets <>. That is just information on what the command is doing.
<make sure no conflict with another version of adb server running>
<checks to see if phone is connected to adb>
adb push system /system
<make sure you type a space before “/system”>
adb shell chmod 6755 /system/bin/su
adb shell ln -s /system/bin/su /system/xbin/su
<make sure you type a space before “/system/xbin/su ”>
8. System is now rooted. You can unplug the USB cable now.
9. Now in Clockworkmod Recovery choose “unmount system.”
10. Go back to the main menu and choose “reboot system now.”
11. If you want busybox (some root programs such as Titanium Backup require it) on your system go to the Android Market after rebooting your phone and search on “Busybox.” Download and run the Busybox installer by Stephen (Stericson). When you are prompted allow it to have superuser permissions.
http://bit.ly/qIAoXZ <link to Android Market page for Busybox>
12. You are now rooted with a working busybox installation.
13. It is a good idea to go back into recovery and make a backup of your newly rooted system before you start installing and running programs that obtain superuser permissions.
14. Enjoy the power!
Please click the Thanks button if this helped you out.