Jan,
This is a late response to your question because I have only just had the same problem with a new kitchen fit using an integrated Candy dishwasher. THis is how I did it:
(a) Put dishwasher on its back
(b) remove 3 screws either side (you've already done that!)
(c) get a long flat head screwdriver and push it up through the hole at the bottom of the dishwasher between the dishwasher front edge and the front of the plastice side strip that attaches to the fascia panel
(d) Get another flathead screwdriver and gently push this through the gap between the underside of the side strip and the back of the dishwasher edge.
I can't think of another way of explaining this since I cannot draw you how i did it, but i did. Eventually the clips come lose as you wedge the screwdriver and make the gap wider between plastic strip and edge of dishwasher. To conclude, one of the screwdrivers seemed to have widened the metal holes slightly in which the clips were sitting. It worked for me. After this you will be able to put any fasci panel on and off easily. I think the problem is the metal recess hole in the side of the dishwasher itself. Once this was widened then the clip just sat in the hole nicely. (All of this info and you have probably already solved your problem! :-)
J McGregor, September 2009
