When you return your iOS Device (iPad or iPhone) to the IT Service Desk, you need to remove your information as well as any screen lock passwords. This must be done in order for it to be repaired, replaced or repurposed.
Step 1: Back up your data
Note: The IT Service Desk staff do not save or transfer the data stored on any phones, it is your responsibility to ensure you back up any data, contacts, music and pictures you wish to save.
For more information on how to back up your data, see How to back up your iPhone, iPad, or iPod Touch.
Step 2: Sign out of iCloud
Go into Settings, iCloud and tap Sign Out
Step 3: Disable "Find My iPhone"
You also need to check the setting for Find My iPhone, turn this off if it is currently in use.
From your Home screen, tap Settings > iCloud (enter your Apple ID if prompted)
Scroll to the bottom and tap Find My iPhone
Step 4: Erase your Phone
You are now ready to erase your phone. In Settings tap General and then Tap Reset. Then tap Erase All Contents and Settings.
This will remove your iCloud lock on the device and remove all of your personal data. The iPad or iPhone can now be repaired or returned to be repurposed.