Alias Rooms' content cannot be modified because it's just a mirror of the Master Rooms. If you want to turn an Alias Room into a Master independent Room, you have to consolidate it as follows. 

From the Rooms dashboard:

  • Locate the Alias Room, click on the options button on the card, and choose Consolidate Room.
  • In the next dialog, edit Room's data and settings
  • Press the CONSOLIDATE button.

NOTE: As long as you are consolidating an Alias proxy-only Room, the consolidated Room will not carry any originals.