APPLE DEVICES: If you own an Apple product, you will need to disable the activation lock feature on your device before sending it in for donation. Simply sign out of your iCloud before factory resetting it. You can do this by going to Settings > Apple ID > Sign Out. After that, Settings > General > Reset > Erase All Content and Settings.
ANDROID DEVICES: Turn off the phone and then press and hold the Volume Up key and Power key simultaneously until the Android system recovery screen appears. Use the Volume Down key to highlight the “wipe data/factory reset” option and then use the Power button to make the selection.