This isnt a re post because its a different way to do it.
What You Need:
Noggenfogger Elixir
Goblin Rocket Boots
Need Caped LM (if not caped its alot harder)
How to do it?
Step 1: Go to the top of the LM overlooking the BS
Step 2: Equip ur rocket boots and aim towards the bs roof
Step 3: Use the noggenfogger elixir until u get the slow fall for 2 min
Step 4: Use the boots and run towards the BS off the LM Cliff
You should glide right towards it and land on the very top of the roof may need to do it a few times to get the hang of it but it works =P