Just did a full cooling system repair on my 330i and i would recommend to remove the fan to give you more room to remove the lower radiator hose as there is also a sensor to remove and clips to pry off. On my automatic, the fan shroud was blocking access to the lower hose.
My lower hose was never changed till a few days ago and was stuck on super tight. Here's an easy trick to remove the lower rad hose without using extreme brute force. After removing the fan - just grab and squeeze the hose near the end you want to remove and give it a little yank and it should just come right off - easy!
Not sure if 5-speeds are the same as an Automatic, but make sure you change the Radiator/Auxiliary Fan Switch in the Lower Radiator Hose, or you'll get a leak when you reattach the sensor. Peace of mind for $17 for new sensor or just buy a new green gasket for $1.