Add Bb clar to bs. clar part? No option to add another instrument

In an orchestral piece bass clar has a separate part but near the end of the piece takes up a Bb clar. which I would like to be on the part as there is a lot of divisi lines. Can’t find a way to do it. Is there? Thanks

Select the Bass Clarinet player in the left panel of Setup mode. Click the add instrument button at the bottom (or type Shift-I) to add a new instrument, then search for the required Clarinet.

Thanks pianoleo, I actually knew that but for some reason this time thought it was done by highlighting the instrument. Obvious now.