The easiest and cheapest way to get to the hotel from the airport is via SuperShuttle. It’s $13.00 on way if you reserve ahead of time on their website by clicking here. The Marriott is listed as one of their hotel destinations. Simply search for Courtyard Marriott Inner Harbo.
And be sure to use the code PGRV7 for $2 off! Thanks @amnichols for finding that!