IMPORTANT NOTE: This article refers to WP Ultimo version 2.x.
Canceling a membership on your customers side is pretty easy.
If your user wants to cancel their membership, they should first access their Account page.
There, they should click head to the Danger Zone, and click to Delete Account.
A module will open asking for their confirmation. They should toggle the Confirm Account Deletion option on and click to Delete Account.
This will log them out of the site and cancel their membership on your network, as well as delete their site from your network.
Important: Notice that this action will not exclude the customer from your network, since a customer can have more than one membership or none membership linked to them.