how do I empty the water out of the radiator on a Volkswagen Passat 2003

Unscrew the drain on the bottom of the radiator..it's that simple. There is one there

There is also an engine block drain on the driver's side of the engine near the oil filter flange.

hey Dave, just out of curiousity is this one of these "counterflow" radiators, like the Tercel used to have?

you know it, the t-stat is on the lower hose--kinda logical, heat rises, why not coolant? not sure this idea stuck...

If you're having trouble getting that 10 year old drain to work, pull off the lower radiator hose. --- I remember there was one car that had the thermostat right at the top of the radiator. I was helping with some maintenance and the owner opened the cap, pull the old one out and dropped a new one in.