Hi @PSchleker, I hope I understood your desire (if not, sorry).
To move the instrument at the desired position in a kit, you need to edit the Percussion Kit, switching to the Grid panel (which is your current visualisation for that kit, as defined in Layout Options > Players > Percussion).
And once you are in the Grid panel of the dialogue, you can move your instrument positions:
Add-on:
if you also want, for some reason, the stem direction to follow exactly the voice assignments in the edit percussion kit dialogue (otherwise, with only one instrument playing in a specific bar, the stems will point to the middle of the grid), just activate the Drum set checkmark:
