It's really easy, i replaced the radiator in my 325e a month ago. Drain the coolant at the bottom of the radiator,then remove the hose clamps. Unbolt the two bolts that hold the radiator in, and unclip the plastic piece that directs the airflow to the fan. Leave this in. Pult the radiator out and streight up. It sits in rubber vibration dampers in the bottom. Installation is the reverse. Oliver