exchanging staff and tab positions

I use Musescore 2.0.3 with Windows 7.

I am writing a score for cittern and viol, with a staff and a tab lines, linked . All is well, except because of the way I started, with the staff, and then inserted the tab , the cittern tab is placed below the viol staff.

How can I get them the right way up, that is, tab above staff?