Stop sharing one or more Devices with other user(s)

If you have shared one or more Devices to another user and you now want to remove Sharing, select the Device(s) and then choose "Unshare" from the "Actions" menu.

Use the contact picker to choose the Contacts from whom you wish to remove Sharing on the selected Devices, then click on "Remove Sharing".

While it's not possible to "undo" this action, you can easily share any Device again with another Contact.