Converting a Non-Percussion Staff With Notation To Percussion Staff With One Line

I am constantly working on exporting Cubase Pro 10 XML files and importing them into Dorico Pro 3. When doing this I have a couple of percussion parts (e.g. snare drum) that are importing as a standard 5-line treble clef and not percussion staffs. I am looking for a way to convert these non-percussion clefs to a one line percussion clef without adding a new percussion part and copying and pasting the notation from the treble clef to the percussion clef then deleting the undesired part. In setup mode I have also tried to change the snare drum to another non-pitched percussion instrument but Dorico Pro 3 is not giving me a fill instrument list but one that has removed the non-pitched percussion instruments making it so I cannot select a different instrument in this category. I have also gone into layout options > Players and the percussion tab is missing (I have seen a few videos online where this tab existed but it appears that it has been removed). This tab also does not show up for the added percussion instruments when I select them. Thanks in advance for your help.

Welcome to the forum, cjbarnet. You can’t change a pitched instrument to an unpitched instrument, but you should be able to copy and paste from a pitched instrument to an unpitched one easily enough. The reason you don’t see the Percussion section on the Players page of Layout Options is that the layout you’re looking at doesn’t have any players holding percussion kits.