iPad
First, back up any files that you have on the device and that you want to keep.
Then, click on “Settings” to find the place where you can sign out of the iCloud or iTunes and App store.
Click on “your name” in the upper part of the menu. In the photo below, the name is blacked out to show where your name would appear.
The option to Sign Out will appear in the lower part of the menu on the right. Click on this to sign out.
After you’ve signed out, click on the “General” tab in the menu on the left.
Then, select “Reset” from the lower part of the menu on the right.
From the Reset page, select the option to “Erase All Content and Settings.”
At this point, you will be prompted to confirm your intention to delete all media and data, and to reset all settings. Confirm this by selecting, “Erase.”
If asked for your device passcode or Restrictions passcode, enter it. Then tap, Erase [device].
If applicable, remove your old device from your list of trusted devices.
iPhone
First, back up any files that you have on the device and want to keep.
Then, click on “Settings” in the lower right-hand corner to find the place where you can sign out of the iCloud or iTunes and App store.
If you’ve logged into the phone using your Apple ID, click on “your name” in the upper part of the menu. Then click, “Sign Out.” This step is not pictured and does not apply if you didn’t set the phone up with an Apple ID.
After you’ve signed out, click on the “General” tab in the menu.
Then, select “Reset” from the lower part of the menu.
From the Reset page, select the option to “Erase All Content and Settings.”
The option to “Erase iPhone” will appear at the bottom of the screen. Click this to erase the content and settings of the iPhone.
At this point, you will be prompted to confirm your intention to delete all media and data, and to reset all settings. Confirm this by selecting, “Erase iPhone.”
If asked for your device passcode or Restrictions passcode, enter it. Then tap, Erase [device].
If applicable, remove your old device from your list of trusted devices.