The way to tackle this is to handle it as you would any newspaper report. You will need to answer these questions: who, what, why, where, when and how.
The two people involved in this scene are Macbeth and Macduff. What is happening is that the battle for Malcolm to regain the throne of Scotland is reaching a climax and this is the final showdown. Why Macduff is the one to face Macbeth is that he is seeking revenge for the murder of his wife and children, but also that he is the only one who can actually kill Macbeth. Where this happens is at Dunsinane. When it happens is as the battle between Macbeth's supporters and the invading army of English soldiers and nobles loyal to Malcolm is under way. When considering how, you can then give details of the exchange between Macduff and Macbeth and give some information about the fight and its outcome. When writing a newspaper article, you are reporting the facts, but also trying to grab the attention of the readers, so choose a striking headline as a title for your article.