Guide on modding audio using my own tool, PD3AudioModder
Replacing music can be trickier, as it usually has to be the same length as the original. Custom Heist Track Tutorial/Guide may be better.
For more complex sfx replacement, it is recommended you follow this guide by Gamest23 instead.
Otherwise, this tends to work fine for simple replacements.
This guide assumes you know some basic Windows knowledge like extracting .zip files and using command prompt.
PD3AudioModder handles all this for you:
Converting audio to WAV + little endian
Editing the HEX data of .uexp files
Packing files
Viewing, playing and exporting sound files as uasset, ubulk, uexp/wav
older guide available here that uses Wwise and some scripts for those interested.
