There are various solutions for performing hard reset for Samsung S3 Lite GT-S6790. Note that hard reset will delete all data that your device contains including apps ,pictures, contacts, messages, etc.
METHOD 1
Turn on your phone and navigate to setting icon.
Scroll down to the last menu at the bottom.
Click “System.”
Select the option labeled “reset options.”
choose “factory data reset” option.
Tap the last “reset phone” to confirm you want to erase all data.
Enter a correct pin or pattern and select “yes erase everything” to continue.
Congratulations you are through! Wait your phone to restart and complete the initial setup.
METHOD 2
Power off your Samsung S3 Lite GT-S6790device
Press power button, volume up key and home button all at the same time until the Samsung logo appears
You will be taken to the recovery mode on your Samsung S3 Lite GT-S6790
Select “wipe data/factory reset” by scrolling using the volume down button and confirm using the power button key
Select “yes—– delete all data” and accept by pressing the power button