Bleeding coolant on 1.9 tdi

hi . if you take the battery cover off you will see two black rubber pipes going through the bulkhead these go to the heater matrix behind the dash there is a small hole in the top of one of them i think its the left one as you stand in front of the car. when you have refilled the coolant start the engine then loosen the spring clip off the pipe with the hole in and pull it forward just enough so that the hole is just off the end of the pipe . dont remove the pipe completely by doing this you will allow air to escape out of the hole when all the air is expelled push it back on fully