Hi Lucius Snow, if the aim is to keep the original structure with menus and extras, make a copy of the original structure of the movie, delete folder SSIF, use tsMuxeR for replace audio, selection output BluRay folder, replace two m2ts and clpi, rename them as originally number, main mpls rename inside using hex editor, insert them in the original structure, download DVDFab virtual drive is free:
https://www.dvdfab.cn/virtual-drive.htm
enter to menu, selection create mini iso, point to the newly created folder, the structure with the SSIF folder will be recreated.