You will need the Full Write Service Plans permission to perform this action.
Go to the service plan you would like to change the type for, and then choose Actions > Change service type in the upper right.
A pop up will appear where you can choose the new type. You can also indicate if you want all future service plans for the same type to be updated as well.
Important: Changing the service type will not affect any currently scheduled teams. They will remain on any updated plans even if they aren't part of the new service type configuration.