Ferrari edition chrono function

[Roy_S]

I've just acquired a Ferrari edition Panerai second hand, warranty card is dated 2006 & it's the one with the seconds dial at 9 o'clock & the chrono minutes at 3 o'clock. The watch is in very good condition with both straps, box & papers but no instructions? I can't for the life of me figure out how the chrono function works, the obvious buttons won't push in. I wondered if anybody here can help before I admit defeat & send it back? Thanks in anticipation.