Long press the item to view these options:
The first one allows you to delete the credential (and all of the services bound to it). The second one allows reauthenticate it. And the third is to rename it.
Double press the logo to reauthenticate.
Double press the name to rename it.
The name of the service is used only for information purposes. You can authorize the same service with different credentials (username and password) and name each one as you wish.
There is no possible to have same online service with same username and password more than once.