Here's how:
1. Find the three golden bricks hidden near the willow. These bricks are usually found in the branches or behind some leaves.
2. Use the three golden bricks to build a platform in the center of the clearing.
3. Place the platform in front of the willow.
4. Have a character stand on the platform and use the "Lumos" spell to illuminate the willow. This will cause it to calm down and allow you to pass through.
It's not about defeating the willow but about finding the hidden secrets and using them to peacefully navigate its defenses.