We recommend you perform a "master reset", but make sure you back up your device first. Here are the steps you can take to master reset.
Again, back up important data on your phone before restoring factory settings.
Restoring factory settings will erase all personal data from your phone, including fingerprints, account information, downloaded applications, and application settings.
- Open [click to enlarge] Settings.
- Touch Advanced settings > Backup & reset > Factory data reset.
- Choose whether to format your internal storage, and then touch Reset phone.
Selecting Erase internal storage will delete all files on your internal storage, such as music and images. Proceed with caution.
Touch Reset phone to restore your phone to its factory settings. Your phone will restart automatically when the process is complete.
You can also hold the power button and volume button for 30 seconds until the device resets, then follow the prompts to activate the device. (NS)