The RIAM and TCD are most easily reached via DART or commuter train to Pearse Street Station. See http://www.irishrail.ie/ for more details.
Both venues are well served by Dublin Bus services. For more details see https://www.dublinbus.ie/Your-Journey1/City-Centre-Bus-Stops/Nassau-Street-Bus-Stops/, http://www.dublinbus.ie/en/Your-Journey1/Timetables/?, and https://www.tcd.ie/Maps/directions.php
ROYAL IRISH ACADEMY Of MUSIC, 36-38 WESTLAND ROW DUBLIN
TRINITY LONG ROOM HUB, TRINITY COLLEGE DUBLIN