RADIATOR COOLANT REPLACEMENT BMW E36 1992

Seeing as you just replaced the water pump, there should be little fluid remaining.

Remove the drain plug from the bottom driver's side of the radiator. Let it drain into a large pan. Once draining is complete, remove the bottom radiator hose from the passenger side of the radiator just to get everything out of the engine if the engine block drain plug didn't remove all of the fluid. Replace the plugs and lines if removed.

Fill the radiator reservoir and start the engine with heat controls on high. open the bleed screw beside the filler cap just enough to let air out. Keep refilling reservoir as the engine sucks it into the radiator. Only fill it to the cold line. Once it stops moving below the Cold/KALT line, replace the cap and close bleed screw.