If by airport, take Pine Island Taxi to the Safe Harbor Pineland Marina.  It is a one hour drive and Pine Island Taxi is the best.  

From Safe Harbor Pineland Marina, take (BOOK EARLY) the Island Girl Ferry - http://www.islandgirlcharters.... - Every two hours starting at 7am.  

You will be met at Mainstay Marina (aka Barnacles bar) by your island host. They will take you by golf cart to Las Olas. Oyster Shell Dr is the 3rd to last road as you head south on Rum Road. Las Olas will be on your left, just past Sandy Paws - pull through the main entrance and park the cart.