Hi Ste, it will dpend on the model as they were made by different manufacturers.
If the control panel is black and under 5 yrs old.Open the door flat.look at the lowest 2 screws,they should be wood screws.Undo them, slightly close the door to an angle of 45degs and slide the door down,this should release it from the panel.
If the panel is white, open the door flat, SLACKEN screw 2 and 4 both sides (counting from base not top)
Close door slightly as before , pull out and down,this will release it.It will again depend on the fitters as this is manufacturers instructions,if the fitter did not want to use these details he may have glued, screwed, anything to make it fit.All the best.
FOXY, September 2008