If the bonnet opens just a little but is still locked then use a long flat screwdriver. Lift up the bonnet as far as it will go and you should be able to see the hook with a hole in the side of it. Use the screwdriver to prise the hook to the right, it will take a lot of fiddling but it does work. This will only work if it opens a little when you pull the bonnet release lever inside the cabin.
george
June 2010