It is possible to reassign a machine to a new user in just a few clicks. Note: This feature is only available to team administrators.
Start by clicking on the machine to view the machine details page. Here you will see a Reassign button (see highlighted button in screenshot below). Click to open the Reassign Machine dialog. Here you can either start typing the user's name/email address or view the dropdown list by clicking the arrow on the righthand side. Once you've selected the user, click Reassign to complete the process.