To manage your smart lists to go to the Admin > Manage Lists screen. You can also access it by clicking on the cog icon in the row of smart lists from the People screen.
On this screen you can rename, edit descriptions, toggle sharing and delete smart lists. Only admin users can toggle sharing. You can also add best practice smart lists.
Click on either the name or description of a list to edit it. To toggle the sharing of a list, click the shared checkbox. Shared lists are able to be used by all team members on your account. Click the trash can to delete a list.
You can also reorder lists by using the handles located on the left of each row. The list order will be used the next time you go to the people page.