Number 9 Bus- You can catch it at Boston Public Library/Copley- or at the Broadway Redline Stop. (see the below train section). The bus needs to say City Point on it. Get off at K Street & East Broadway. Number 7 Bus you can catch it at South Station. Get off at the corner of East First Street and Summer Street.
Closest MBTA train stop Redline Broadway stop- then take the catch the Number 9 bus (stop is across from the Dunkin Donuts). The bus needs to say City Point on it. Get off at L Street & East Broadway. Cross Broadway to walk down L St. Keep going until you reach almost the end of 840 Summer Street.