[Samsung Epic 4G Touch] zedomax:
For those of you who need to unroot your Epic 4G Touch back to "completely" stock with no root whatsoever, here's a step-by-step guide.

*note - if you are not on a rooted stock ROM, you will need to restore your phone to a rooted stock ROM first, you can get a copy of rooted stock ROM here if you forgot to make a backup.

Step by step tutorial for beginners:

[YOUTUBE]tAn3vOlLjZE[/YOUTUBE]

Step 1. First, put your Epic 4G Touch into download mode by holding down both Power button and Volume Up button together. Then connect a USB cable from your phone to your computer.

Step 2. Open up ODIN. You should have this program already when you rooted your phone but if you don't download ODIN here:

Download ODIN v.1.85

Step 3. You should see a yellow COM: show up in ODIN, the number doesn't matter so long as it shows up like in above screenshot. If it's not showing, you need to install Samsung Kies. (Download Kies here)

Step 4. Download acs-eg30-stock-kernel-pulled.tar at ACS site under Downloads.

Choose "PDA" then choose this file you downloaded, acs-eg30-stock-kernel-pulled.tar.

Step 5. Hit Start and your phone should reboot with stock boot logo.

For Linux and Mac users, you can use Heimdall instead of ODIN, use the same tool but flash this stock recovery acs-eg30-stock-kernel-pulled.tar instead of rooted kernel.

Step 6. Now, you should have a fully stock rooted Epic 4G Touch. At this point, you should still have your apps/personal data. If you just want stock rooted Epic 4G Touch, you can stop here. Otherwise go to Step 7.

Step 7. If you want to completely unroot your Epic 4G Touch, you will need to erase root and Superuser app files. To do this, you can use ADB or Terminal Emulator app. If you are using Terminal Emulator app, skip to Step 10.

Download ADB.zip here if you don't have it already (works for Windows, Linux, and Mac):

Download ADB.zip

Unzip(uncompress) ADB.zip into your hard drive, I prefer C:\adb (for Windows).

Step 8. Browse to the directory of your ADB files by typing:

For Windows:

cd \adb

For Mac & Linux:

cd /adb

Step 9. Get into ADB shell, type:

For Windows:

adb shell

For Mac:

./adb-mac shell

For Linux:

./adb-linux shell

Step 10. Type the following commands to erase rooting and Superuser files:

su
mount -o rw,remount -t yaffs2 /dev/block/mtdblock3 /system
rm /system/xbin/su
rm/system/bin/su
rm /system/app/Superuser.apk
reboot

Step 11. Your Epic 4G Touch will reboot and you can double-check now that Superuser app is gone plus rooted apps are not working any more.

Step 12. Lastly, if you want to erase all your personal data and apps for returning to Sprint warranty, you can get into stock recovery by holding down both Volume up and Power button together for about 10 seconds.

Step 13. Choose wipe data/factory reset using Volume keys then hit Power button.

Step 14. Choose "Yes -- delete all user data" using Volume buttons and hit the Home button.

Step 15. Reboot your Epic 4G Touch and you should have the same exact phone you got the day you bought it.

Step 16. And also, make sure to connect your Epic 4G Touch as a disk drive and erase your personal files.

*****Credits*****

HUGE thanks to Bubby323 for pulling stock kernel! - hit up Bubby323's "Donate to me" button here