I've been struggling with something for a couple of weeks now and am becoming very desperate for an answer. What I'm trying to do is take a Blu-Ray which I have created from a DVD using DVDtoBD Express and replace the main video files on there to my own authored video files that are better quality but keep the menus. Then burn the updated files to a BD-R disc. I'm not sure if doing something like this is possible at all due to the fact that I've found little to no threads related to this.

I tried using multiAVCHD but for whatever reason, it's not allowing the files to be replaced and then put on the disk properly. If anyone can direct me to a program that might help or tell me this isn't possible that'd be greatly appreciated. Thank you!