When you want to sell your mobile and buy a new one, you must reset it before selling it. You might have any personal data on your mobile. Doing a factory reset will erase all the data in it. But always keep a backup of your personal data before reset. So you can restore it on your new mobile. This is one of the reasons for doing a factory reset. The other reason is if your phone is experiencing some problems, you can reset your phone to troubleshoot it.
Go to the Settings app. Scroll down the menu. Find the option “General Management”
Step 1. Go to Settings
Step 2. Click the General Management tap
Step 3. Click Reset
Step 4. Press Factory data reset button
Step 5. Scroll down and search the blue “Reset” button.
Step 6. Now enter the pin and press Next.
Step 7. Click on the “DELETE ALL” button
After doing this, your mobile will auto reboot. It will take some time to reset. After some time, your mobile is all set and becomes like a new phone.