If you log in with the same account with which you registered the relay team and the online registration is still open then you, as registrant, can edit the relay team yourself.
This can be done by going to the competition --> Register (top green bar) --> Club.
There you will see a "My Relay Teams" button, there you can edit your relay teams. If you click Edit, at the bottom you will also see a button to delete the team in its entirety.
This has been automatically translated into English