• Restart your phone in ODIN mode by pressing Volume Down + Home + Power
• Register and download your stock firmware from sammobile.com
• Unzip the downloaded firmware
• Download ODIN from xda-developers
• Don't uninstall Kies as you'll need the driver
• Open ODIN and connect your phone to computer(Phone should be in ODIN mode)
• When your phone is detected it will be listed under comX
• Under PDA select the extracted firmware you downloaded (Select the file with .tar.md5)
• Only the checkbox for PDA, Auto reboot and F. Reset time should be checked
• Click start to start your flashing
• Your phone should reboot with stock firmware

Note: You'll loose all the offline content from your phone

• Restart your phone in ODIN mode by pressing Volume Down + Home + Power
• Register and download your stock firmware from sammobile.com
• Unzip the downloaded firmware
• Download ODIN from xda-developers
• Don't uninstall Kies as you'll need the driver
• Open ODIN and connect your phone to computer  (Phone should be in ODIN mode)
• When your phone is detected it will be listed under comX
• Under PDA select the extracted firmware you downloaded (Select the file with .tar.md5)
• Only the checkbox for PDA, Auto reboot and F. Reset time should be checked
• Click start to start your flashing
• Your phone should reboot with stock firmware

Note: You'll lose all the offline content from your phone