Middle level - Pick up the Health Potion and approach the egde of the walkway facing the device. Wait for one of the three floating platforms that move around the device to approach and jump to grab it. |
Pull up and wait a bit as the platform circles around the device. |
Turn having the device to your back and wait for the platform to reach the ledge with the ring. When it does so, jump to the ledge. |
Climbing down to the lower level - Use the Grapple to catch the metal ring and step back off the edge. |