Root for Apps2sd, JIT, and Nextheme/Genesis

First of all, get the android sdk files HERE. Then, open the exe file and install all the necessary packages, especially the USB Driver for windows. Rename the sdk folder to android and put it into your drive c:/

Download the necessary files (Depending on which flash rom you choose)
European - STR_U2_01.1E.0
Italian - STR_U2_02.1E.0
Russian - STR_U2_03.20.1
US CBW - STR_U2_04.1E.1 - Megaupload link
*Update 8/29/2010 - Script has been updated to let you chose which options to install and a modified version of the NexTheme with LauncherPro has been added
If you have already run the script just run it again and say "n" to installing APPS2SD and JIT in order to get the NexTheme installed

Credit for the 2.2 JIT compiler goes to antibyte for the Frozen Eclair project
Credit for the original apps2sd instructions/script go to jakelights for finding the script and whomsoever wrote the script (not referenced in forum post)
I TAKE NO RESPONSIBILITY IF YOU DAMAGE YOUR PHONE!

THESE INSTRUCTIONS ARE PROVIDED AS-IS AND BY APPLING THESE TO YOUR HANDSET YOU TAKE FULL RESPONSIBILITY FOR THE CONSEQUENCES!
Step One: Create an ext3 partition on your MicroSD card
This step is tricky, and the only reliable way I have found is to use gparted under linux with your microSD inserted into a card reader. THIS LINK will provide instructions for use a gparted live CD so you do not have to install linux on your computer.

1. First create a fat32 partition at the beginning of the drive leaving about 1GB of empty space (more or less depending on how much space you want for installing apps)
2. In the empty space create a linux ext3 partition
3. Flag the fat32 partition as boot
4. Apply changes

Step Two: Copy files to the microSD card
This presumes you have already placed the microSD card back in the phone.

* Unrar the attached file to the root of your microSD card. It's critical to running the script later that the path to the apps2sd directory be /sdcard/apps2sd
Step Three: Install the necessary applications
Make sure you are already signed into a Google account so you can access the market!

* In the Market download an app called Estrongs File Manager
* In the Market download an app called BusyBox
* In the Market download an app called Milestone Overclock
* Open Estrongs File Manager (listed as ES File Explorer in your app drawer) and you should, by default, be seeing the files/directories on the sdcard
* Tap on UniversalAndroot.apk and use the Package Installer to install the application
* Ignore the Milestone Overclock APK included and instead use the latest version in the market!

Step Four: ROOT!

* Run the Universal Androot application and tap on Root :-) (wait for it to finish before going back to home screen)
* Run the BusyBox application, tap on Install, then tap on OK when the Superuser Permissions dialogue box pops up.

Step Five: Run the script
In order to run the script from your handset you would need a terminal application installed and the script will try to move the application while running ... NOT RECOMMENDED! (see post #3) Please only run this script using ADB access from your computer. I've uploaded another guide I wrote on setting up ADB access on a Windows computer and attached to this post.

Next, simply connect the XT720 to your computer.
Ensure it is "Charge Only" for USB connection and USB Debugging mode for USB is turned on under Settings > Applications > Development.
Once you have the above checked, go ahead to launch a command prompt and perform the following:

Type: cd c:\android\tools
Type: adb devices

* Once you have a device showing under adb devices type in adb shell
* Make SURE your screen is unlocked then type in su, hit enter, and tap on OK for the Superuser Permissions box that will pop-up on the handset
* The command prompt should change from $ to # indicating you now have root access to the file system
* Run the following command: cd /sdcard/apps2sd
* Run the following command: sh install.sh and enter a y when asked if you want to proceed (assuming you do)
* Enter a y when prompted to reboot

IT WILL TAKE 5 - 10 MINUTES TO REBOOT - THIS IS PERFECTLY NORMAL - TIME VARIES DEPENDING ON AMOUNT OF APPLICATIONS MOVED AND SPEED OF YOUR MICROSD CARD

Once your phone boots up apps2sd should be working, JIT should be enabled, and you are good to go! Use the Milestone Overclock application if you want to see some extreme performance boosts!
*Qoute from droidforum site*