Activate Mishra's Factory's first ability by tapping it, adding ({C} magic symbol) .
Activate Mishra's Factory's second ability by paying ({1} magic symbol) , causing it to become a 2/2 Assembly-Worker creature that is still a land until end of turn.
Cast Exchange of Words by paying ({1} magic symbol) ({U} magic symbol) ({U} magic symbol) , exchanging the text boxes of Mishra's Factory and Scute Swarm.
Play a land.
The land enters the battlefield, triggering Mishra's Factory's Scute Swarm ability, creating a copy of Mishra's Factory with its original text.
Step 5 repeats in a mandatory loop unless interrupted, drawing the game.