If you somehow control two or more Breeches, Eager Pillager, track which modes have been chosen each turn for each one's ability separately.

If you can't legally choose a mode because all three have been chosen that turn, that instance of the ability is removed from the stack with no effect.

You pay all costs and follow all normal timing rules for cards played this way. For example, if the exiled card is a land card, you may play it only during your main phase while the stack is empty.