You’ll find out main entrance at Tödistrasse 48. On the right hand side of the building you’ll find a lockbox for the key. The code is 2611. After retreiving the key make sure to close the lockbox again, enter the building and go up to the 4th floor. If the glass door is locked, one of the keys on the ring will unlock it. On the 4th floor make a left, walk down the hallway and unlock the studio door with the other key.