In the Water
When you reach the top of the lift, take a right and go past the orange raft. You will see a decline headed straight to the lighthouse. Start heading down but be slow about it
and keep your arms out in case you need to grab onto the mountain so you don't fall all the way down. When you actually get to the lighthouse you'll have to climb a bunch of stairs to make it to the top. Once you finally reach the top pull the lever
and the light should turn on.