A Lawfirm has placed a levy on my bank account because of a Credit Card bill owed by my common law wife. Her name is also on my account. How do I get a release from this levy.

You pay the bill.

Unless you are claiming that the credit card bill is not valid or that your c/l wife has no claim on your funds, its unlikely you will get it removed. You need to find out the court that issued the judgement and file to vacate the judgement.