In this example, we only changed the ION cannon sound effect, but you can continue to change other sound entries in the bnk if you like. After I finish my changes, I hit the save changes button to build a new guns.bnk file in the same, working directory. Two other files will be created: guns.bak and guns.bak2. These aren't really important right now. This process will make a copy of the bnk file, append the raw sound effects to the end of it,and then update the header to reflect the new sound offset and the new sound parameters. Now, I can copy the new guns.bnk file back into the soundfx directory under the homeworld game install directory and start the game.