How to create stacked polychord symbols

1. Download and save the file "fracchords_0.xml" (by underquark in Option for creating stacked chord symbols (chord names);
2. Copy it (or drag it) into the folder: MuseScore/Styles (confirm the authorization, if requested);
   
3. Enter chord names as from handbook;
4. From the main menu, choose Style → Edit General Style...;
5. From the left pane, select Chordnames;
6. Navigate to the styles folder if necessary;
7. Select fracchords_0.xml;

Done!

Remember that: When properly inserted, the chord names can be transposed