1.
Browse to the directory “C:\Program Files (x86)\StarCraft II Beta”
2.
Create a folder called “SWF” and another inside of it called “Authentication”.
3.
Open “StarCraft II Beta\Battle.net\Battle.net.MPQ” with the MPQ archiver.
4.
Extract “Battle.net\SWF\MainUI.gfx” to the same folder that the MPQ is in.
5.
Close the MPQ archiver and rename “MainUI.gfx” to “authentication.gfx”.
6.
Put “authentication.gfx” inside the SWF\Authentication folder and run “Starcraft II.exe”.
7.
Note: The resulting file should be in “StarCraft II Beta\Battle.net\SWF\Authentication\authentication.gfx”.