Take the A, C, or E train to 34th Street Penn Station. From 34th and 8th Ave, it's a 10 minute walk southwest.
Coming from New Jersey, take the Lincoln Tunnel and turn right off 31st.
Coming from Upstate/The Bronx, head south on the Henry Hudson Pkwy to NY-9A S. Look for signs to 42nd Street in Manhattan. Continue south 11th Ave to 31st.