Volkswagen: 2000 vw beetle, allen head screws, coolant system

Question
could you please tell me how to bleed the air out of the coolant system?

Answer
The first thing you need to do is elevate the coolant in the reservoir.  VW has a tube that screws onto the fill hole, but you can also do the same thing by unmounting the tank and holding it up.  Also unplug the connector for the low coolant sensor (don't forget to re-plug it).  The highest bleeder is on the outlet of the heater core.  It's actually a hole on the hose.  Slide the clamp back and slide the hose back so that the hole is off the end of the nipple.  As soon as coolant squirts from the hole, slide it back on and clamp it (, Jed).  There may also be bleeders on the coolant pipes on the engine and these should be bled first.  Look for silver allen head screws going into welded bosses on the coolant pipe.  Not all engines have them.