NOTE: Before you factory reset the phone, you can check this thread for a guide on how to back up data, and this thread for instructions on restoring data on the device.

Factory Reset via Settings:

  1. Open “Settings
  2. Access “Cloud and accounts” and tap “Backup and restore
  3. Optionally, turn “Back up my data” and “Restore” ON or OFF
  4. Return to “Settings” and access “General Management
  5. Tap “Reset” > “Factory data reset
  6. Tap “Reset device
  7. If your phone is protected by a password/PIN etc. enter it and tap “Continue
  8. Tap “Delete all

Factory Reset via Recovery:

NOTE: If your phone crashes, freezes, is unresponsive or otherwise prevents you from resetting it using the method above, you can reset the phone from the recovery menu which can be accessed as follows:

  1. Make sure the phone is turned off
  2. Press and hold “Volume Up” and “Home” simultaneously, then press and hold “Power” too
  3. At the “Android” logo release all the keys and wait for the Android Recovery menu
  4. Once in Recovery, press “Volume Down” repeatedly to navigate to and highlight “Wipe data/factory reset
  5. Press “Power” to confirm
  6. Highlight “Yes – delete all user data” using “Volume Down” and press “Power” to confirm
  7. Once the phone resets, ensure “Reboot system now” is highlighted and press “Power

Reset Network Settings:

NOTE: Resetting network settings will delete all connection data such as Wi-Fi and Bluetooth networks, and will restore data restrictive settings, background data sync settings, and network selection mode to default values.

  1. Launch “General Management
  2. Tap “Reset” > “Reset network settings
  3. Tap “Reset settings” and enter your PIN / password if necessary
  4. Tap “Reset settings” again to confirm

See More: Samsung Galaxy J2 (2017): Factory Reset and Reset Network Settings