This is a question mainly for Daxar, but if anyone else has been able to mod sounds, please help.
I've been using audacity, and I saved my sound in ogg format to overwire the SunLoop.flac.ogg. I ran the recalcSoundManifest.exe program and it did update the sndmanifest.dat. Then I compressed embed.pak. But when I ran the game, the original sun sound still played. However, the game didn't crash.