Logic Pro 9 converting viola part in score editor

[Edgold]

I am trying to get a readable score but am stymied by the viola part which converts to two staves when I want only one. I have been able to fix other clefs (don't recall how.) but I can't in this case. How would I do this (step-by-step please!)?

 

[Edgold]

Partly solved with the help of this page:

https://documentation.apple.com/en/...gWithMessierRevision-43984NOT_SC_1107-1229300

 

[Pete Thomas]

Partly solved with the help of this page:

https://documentation.apple.com/en/logicpro/usermanual/index.html#chapter=31&section=26&hash=apple_ref:doc:uid:TempBookID-ReplacedWhenAssociatingWithMessierRevision-43984NOT_SC_1107-1229300

Why only partly resolved ?

 

[Edgold]

I haven't found that, though I have been able to convert the viola, this seemed to be accidental and I still don't understand completely how I did it. And other aspects of the score reader still seem mysterious. But my Nocturne so far seems well set-up. I will now be able to deal with the header-footer titles, pagination, © info etc. I understand about slurs, expression and other things that need adding.