The one time this happened to me I was lucky and had the over engine hatch, but once I'd got it open and inspected there was nothing whatsoever wrong with any of it. Since then it's be the karate chop (heel of your hand in reality) on the button pushing on the lid to save bruising and that has worked like a charm, not just on mine but 8 years solid of everyone else's at work. I suspect drilling it will actually make it harder if not impossible to open... but I think you have already started that so...
If you now have a ring of metal with a hole in it, put a bit of wood across it and try thumping that rather than cookie cutting the side of your hand..
got it open today, tried various methods and have got it open by give it a good bang in the release button and pushing the hatch at the same time. Thanks everyone for your help.
