*thrash (something) out*
Definition: to discuss a problem or idea in detail until you find a solution or reach an agreement.
E.g.1: I know it’s late, but this is an important problem and we can’t end the meeting until we’ve thrashed it out.
E.g.2: I’ve thrashed out a new performance related bonus system with the wages department.
This phrasal verb can be separated. (E.g.1)