Just replace the data.win from the main file with this one (make sure to have a backup).

If you want to add this to your own mod or another, you can use the undertale mod tool to replace the audio, press the scripts button on the top left, resourse importers, ImportSingleSound.csx and select the .ogg file in the folder, select yes to embeb it, no to umcompress and yes to replace the already existing one.