How do Shias perform Salat behind Sunni Imam?

Aoa, In my office there is majority of Sunni brothers and I perform salat behind Sunni Imam, and also during Jumaah prayers in nearby sunni mosque, but I wonder whether I am doing in the correct way? Like Skipping Qunoot. So I want to know what things should we skip/change while performing with sunni brothers. And what about Salam? Can we do it in Sunni way? P.S: I am not asking about whether it is allowed to pray behind sunni imam. So no discussions about it. I do taqleed of Ayatollah Sistani. Wasalam,