Must have clauses in a partnership exit strategy?

[Corey Meyer]

If a business partner would like to exit their position in a partnership of an investment property with a long-term "buy and hold" strategy how would they do it?  What clauses are vital to have in an operating agreement?  

Is 5-10 years or 10-20 year hold doable in the operating agreement?

Thanks for any help in advance!

Corey