Unfortunately, you can't expunge a bankruptcy from credit reports. The bankruptcy will remain on your credit record for 10 years and will remain in the bankruptcy court records forever.
However, after the 10 years have passed, it will no longer be passed onto credit agencies - so technically you have a clean slate and can start again.
I have heard of cases where people have hired a lawyer to assist with a bankruptcy expungement, but I don't think they were ever successful - and lawyers who take on these cases are generally only interested in the money they will make, whether you win or lose.
One thing that may be worth a try, would be to contact credit reference agencies and try to persuade them that you are a changed person and have 'served your time'. I am not guaranteeing that this will work but it is certainly worth a shot.
Good luck!