Erase the information on your lost device
Sign in to icloud.com/find using your Apple ID (the one you use with iCloud).
If youíre already using an iCloud web app, click the iCloud button to switch apps.
Click Devices, then select the device you want to erase.
In the deviceís Info window, click Erase Device.
Do one of the following:
To erase an iOS device, enter your Apple ID password, then click Erase.
To erase a Mac, enter a passcode that youíll need to use to unlock the device if you find it (to prevent anyone but yourself from using the computer if itís found), then follow the onscreen instructions.
When asked to type a message, you may want to indicate how to contact you if the device is found. For example, ďThis Mac is lost. If found, please call me at yourphonenumber.Ē
If the device is online, the remote erase begins within seconds (if the device is a Mac, it also restarts before itís erased), and a confirmation email is sent to your Apple ID email address (the one you use with iCloud).
If the device is offline, the information is erased the next time itís online.