you can remove the centre console around the gearstick, handbrake etc, then remove the plastic box with 2 pipes that meet with the floor, behind that you unclip the front of the heater box which is a plastic thing with about 6 clips on it. once that is off you can see the heater matrix. now remove the 2 pipes that go into the bulkhead, they have quick release end on them. you can now go backj in the car and just pull out the matrix. i got one from a radiator company for about £50, £35 quid cheaper than from vauxhall. good luck
Mick jones, June 2005