If you are returning your Galaxy Tab 10.1 to the store, perhaps for warranty, here’s how to unroot your Galaxy Tab 10.1 so no one can tell you’ve rooted before (and unvoid warranty).
Before we begin, if you are going to be returning your Tab 10.1 for another one, you can backup your current ROM (with all your settings/apps) first and save the backed-up files in your computer.
First, download and flash the stock OTA Android 3.1 for Galaxy Tab 10.1:
Download stock OTA 3.1
Use ROM Manager to install the OTA ROM, this should get you rebooted back to stock.
Now, you also need to install back the stock Recovery so download this zip file and unzip:
Put your Galaxy Tab 10.1 in ODIN download mode by holding down both Power Button and Volume Down button and let go when your Tab 10.1 reboots, shows Samsung logo, then 2 menus.
Hit Volume Up button and your Tab 10.1 should be in ODIN download mode.
Open up Odin3v1.85.exe program.
Choose PDA and choose the file “stockretail.tar.md5″ and hit “Start”.
Reboot your Tab 10.1 by holding down the Power button, now your Galaxy Tab 10.1 is unrooted back to stock.