1. Download PC ODIN 1.85 here and download the N7000XXLTA firmware here
3. Click [Start] to install new firmware.
It's NO WIPE. All apps intact but ROOT removed.
Get Philz to root your phone here. Download it and copy it into your external SD Card to flash via Samsung Recovery.
How to go to Samsung Recovery?
1. Power Off your phone
2. Press Home+Volumne UP+Power Button and hold until its boot to recovery.