In case I forget

Here's how my 18-volume EPUB can be updated. I will assume that the tools used are Calibre EPUB software and Musescore.

To update the SVG images:

1. Open the MSCZ file for the chapter.
2. Adjust the Hebrew above the text to correct the te'amim as required. You may need a real word processor to format and type the Hebrew correctly. I could not copy Unicode from mgketer because it does not use the standard Unicode that I read to generate the music from the database.
3. Adjust the music to correspond to the Hebrew in accordance with the deciphering key. This you have to do by hand depending on the change to the te'amim that you are making. Adjust barring if needed -- join or separate bars with the tools menu. Adjust the bars changed to dotted. Or select them all and make them short lines. Bar lines are largely irrelevant in any case.
4. Check the lines for alignment of the Hebrew.
5. Export to SVG.
6. Run the batch file for the chapter to rename the files to what is expected in the EPUB.
7. Delete the EPUB SVG files for the chapter.
8. Import the new SVG files.
9. Change the Hebrew in the html file - the section that shows the te'amim only, to agree with the changes made in the MSCZ file.
10. Delete the SVG files on your computer.

The English guide can be changed in the html file as needed.

To underlay a new arrangement with language other than Hebrew:

1. Open the MSCZ file for the chapter.
2. Adjust the page length to the size you want to your score to be. 
3. Follow your musical imagination. Here are some of my earlier thoughts on this process.

At the moment I am not making these files public. If you want them now as opposed to whenever, let me know. Best step on the road for this is to buy the first available EPUB. Or write a review.

Best approach might be to get in touch with mgketer.org and write a program that will translate their Aleppo Codex text into music using a deciphering key. This is a long process filled with learning.