From NYC, you can take the bus or Amtrak to South Station in Boston. At South Station, take the T on the Red Line to JFK/Umass stop. Then follow the walking directions describe on the left. From Providence, you can take the MBTA commuter rail to South Station, then follow the directions from South Station.
From downtown, take the Red Line train to JFK/Umass station. When you get off the train, be sure to go to the exit at the center of the train platform. When you exit, take the Sydney St exit. Walk down Sydney St until you reach Moseley St, turn left on Moseley St and walk until you see the address. This should take around 5 minutes from the JFK/Umass T station to the homestel.