[Guide] Install Stock T999UVALEM ROM on T-Mobile Galaxy S3

It has begun! The first custom ROM for the T-Mobile Galaxy S3 has been released, and while it may not have as many features as one would expect from a custom ROM, it’s a start and should pave the way for future custom ROMs. Released by RootzWiki developer Whitehawkx, the ROM is based on the UVALEM firmware and is almost stock, but comes pre-rooted and also removes some of the bloatware T-Mobile apps that come preinstalled on the phone.

Here’s the full list of features of the ROM:

Completely deodexed
Rooted
Busybox
Zipaligns at first boot
Carrier IQ stuff removed
Slightly debloated (removed like 8 TMO apps)

Read on to find out how you can flash the rooted stock T999UVALEM ROM on your T-Mobile Galaxy S3.

Compatibility

This hack and the guide below are compatible only and only with the T-Mobile Galaxy S3, model number T999. It’s not compatible with other US variants or other devices. Check your device’s model number in: Settings » About phone.

Warning!

The methods and procedures discussed here are considered risky and you should not attempt anything if you don’t know completely what it is. If any damage occurs to your device, we won’t be held liable.

How to Install Rooted Stock T999UVALEM ROM on T-Mobile Galaxy S3

This procedure will wipe all your apps, data and settings (but it will NOT touch your SD cards, so don’t worry about those). Backup your Apps and important data — bookmarks, contacts, SMS, APNs (internet settings), etc. This Android backup guide would help you.
Important! Don’t forget to at least make a backup of your APN settings, which you can restore later if your data connection does not work after installing the ROM. Use the backup guide to find out how.
Install ClockworkMod recovery on your phone by following the guide → here.
Download the latest version of the ROM from the official development page.
Copy the downloaded zip file from step 3 to the internal SD card on the phone. Do not extract it.
Now, boot into ClockworkMod recovery. To do that, turn off your phone. Then, hold down Volume Up, Home and then the Power buttons together until the screen turns on, then let them go. The phone will boot into ClockworkMod recovery in a few seconds.
In recovery, use the volume buttons to scroll up/down and the home button to select an option.
Perform a Nandroid Backup of your current ROM, so that you can always restore it from recovery if something does not work out with the new ROM. To perform a backup, select Backup and Restore –> On the next screen, select Backup again, then wait for the backup to finish. Keep in mind that at least 1 GB of space is required on the internal SD to make a successful backup. Go back to main recovery menu after backup is complete.
Select wipe data/factory reset, then select Yes on next screen to confirm. Wait a while till the data wipe is complete.
Select install zip from sdcard, then select choose zip from sdcard. Scroll to the ROM file on the SD card and select it. Confirm installation by selecting Yes – Install _____.zip on the next screen. The ROM will start installing.
After the ROM finishes installing, select go back then select reboot system now to reboot the phone.