Step 1 - Extract the GAME.DATS using this tutorial https://www.youtube.com/watch?v=_EQ3h...
              be sure to extract them into the Lego Batman 2 directory, File path: C:\Program Files (x86)\Steam\steamapps\common\LEGO Batman 2

Step 2 - Delete CHARS.FPK

Step 3 - Drag and drop the files into the Lego Batman 2 directory, File path: C:\Program Files (x86)\Steam\steamapps\common\LEGO Batman 2

Step 4 - Launch the Game