how to open

this safe has been in our family for about 20 years it was my mom&dads the kids and friends we all had some fun trying to open it, now our sun is 18 teen and like most still lives at home well he came up with this idea to use a flapper out of toilet and put a hole in the top of it so that a small hose would fit and then my hearing aid in the flapper the peice that goes in the ear is in the hose it works you can here very good with it but we don't have clue on what to do, every locksmith around he say's drill it and that is not what we want to do. Can you give us some help?