Back up your iPhone if needed
Open Settings
Tap General
Tap Transfer or Reset iPhone
Tap Erase All Content and Settings
Enter your passcode
Enter your Apple ID password if prompted
Confirm the erase
Wait for the iPhone to restart and wipe itself
Back up your iPhone if needed
Open Settings
Tap General
Tap Transfer or Reset iPhone
Tap Erase All Content and Settings
Enter your passcode
Enter your Apple ID password if prompted
Confirm the erase
Wait for the iPhone to restart and wipe itself