Creators can manage their recorded livestreams via settings on their user profile.
Access your user profile from the bottom on the bottom panel.
On the user profile, tap the settings button on the top-right of the screen.
A panel will show on the bottom of the screen. Select My previous livestreams.
You will see all of your recorded livestreams in a new window.
You will see an option to edit any of these recorded livestreams.
Select edit, and you will see that particular recorded livestream in a new window.
Select discard to remove this livestream.
Discarding does not REMOVE the stream line item, it still shows the line item as discarded.