Read the full text of Henry VI Part 3 Act 1 Scene 2 with a side-by-side translation HERE.
Back at York's castle, Richard, Edward, and Montague are arguing over something when York comes in and hears them.
When York asks the guys what they were talking about, they tell him they think he shouldn't wait until Henry dies to take the crown—he should take it now.
York tells his sons to cool it. He made an oath. He can't take the crown now, and he promised to be peaceful about the whole thing, too.
Richard pokes holes in this argument. The oath wasn't even properly sworn in front of a magistrate, so it's not legally binding. Plus, wouldn't it be really sweet to wear the crown now?
York is convinced. (That was quick.) He starts to plan his attack. He tells Montague to ask Warwick to join his team; Edward will go to Cobham.
While this planning sesh is going down, a messenger enters with news that Margaret is planning an attack of her own. She's on her way to York's castle right now with her army.
York sends his family to fight Margaret's armies. Also, he warns everyone not to trust Henry and his oaths, because he just goes back on his word. (It doesn't seem to matter to York that he was just planning to go back on his oath, as well.)
As the men go off to battle, York remembers winning in France with fewer men and worse odds. He's convinced he'll win again.