Guide on How to Make a Blu-ray REMUX from a Blu-ray Disc (MKVtoolNix #2)
MKVtoolNix : https://mkvtoolnix.download/downloads.html
Open MKVtoolNix and Select the index.bdmv file from BDMV Folder of your Blu-ray.
Choose the playlist with the most chapters. In this case, the playlist is extremely long (longer than the movie's runtime and chapters), but this is due to a bug rather than the movie itself. So look for the one with the correct runtime and chapters. To determine a movie's runtime, go to https://www.blu-ray.com/.
Click Add and then edit it in the same way we did in eac3to method. (https://rentry.co/uxsh9)
(In this method, the languages are detected automatically.)
You don't need to load the chapter file because it's already there, but it doesn't always get added. As a result, you'll need to extract chapters with eac3to and mux them (using multiplexer) in the final output.