Whew, this is a complex situation. You’ll need a copy of the death certificate and proof that you are in charge of the estate. Read this information about cashing in paper bonds. https://treasurydirect.gov/research-center/history-of-savings-bond/bond-redeem/
It takes as long as 3 months to get them cashed in. Your local bank won’t handle it. And you’ll have to jump through a lot of hoops to prove you are entitled to cash them in, different in each case.