Open a crafting table
Place 1 bow in the center slot
Place 7 cobblestone around the bow in all remaining outer slots except the bottom middle
Place 1 redstone dust in the bottom middle slot
Take the dispenser from the result slot
Open a crafting table
Place 1 bow in the center slot
Place 7 cobblestone around the bow in all remaining outer slots except the bottom middle
Place 1 redstone dust in the bottom middle slot
Take the dispenser from the result slot