Hah - I am answering my own question here, just incase it is useful to someone else with same problem! Since posting the question, I read an answer to someone else's similar problem. The answer is to slide the top off the washing machine by undoing 3 philips screws just under the top at the back. You can squeeze your arm down to hold the bracket in place - however, you do need another person to hold the door in place while you screw it on! Couldnt have done it without my daughter! I had the same problem with the hinge on my dryer but the bracket didnt fall from inside when I removed the screws - you can just take the old hinge off and screw the new one on no bother!
Heidi Burns, July 2006