UK Car Repair: Unable to take off quick release heater hose fitting, vauxhall vectra, tensioner pulley

Question
Vauxhall Vectra 2.5 auto with air con. The tensioner pulley on the drive belt seized shredding the belt and engine overheated. Since then heater is only slightly warm .I cannot get the quick release fittings on the heater hose that goes to the matrix undone so that I can bleed out the air.I have lifted up the small catch and pressed down the small section but I cannot get the hose off Expert advice required please

Answer
You have to be very careful not to put pressure on the matrix fitting, you can easily break it. Why do you want to bleed it there?  Find a way to get the filler neck above the height of the hoses -park on a hill, jack up the vehicle etc.  You can then bleed the system by squeezing the largest hose.