iCloud: Use Lost Mode
Turn off Lost Mode or change your contact info
You can turn off Lost Mode by entering the passcode on the device, or by following the steps below. You can also follow the steps below to change the contact information displayed on your lost device.
Sign in to icloud.com/#find with your Apple ID (the one you use with iCloud).
If you’re using another iCloud app, click the app’s name at the top of the iCloud.com window, then click Find My iPhone.
Click All Devices, then select the device that’s in Lost Mode.
Click Lost Mode, then change the information or click Stop Lost Mode.