If they are in your name, and you are obviously still alive, you can cash them in and pay the taxes on all the accrued interest! Then give the money to your children. The POD designation just tells what happens to the bonds if YOU die, but while you are alive you can do as you want with them.
Or you can request to change the title and gift them to your children, in their own names. BUT, if you completely gift them to your children, by taking your name off, you will be liable for taxes on all the accrued interest.
To change names on Savings bonds, and these are likely paper bonds, you’ll need to go to www.TreasuryDirect.gov and download (under forms), the request to reissue bonds with a new name. Here is a direct link to that form.
Fill it out and take it to your bank to sign it in front of an officer, who will authenticate the signature. There is a list of banks that will do this on the form. Then send the authenticated form and the bonds by registered mail to the address on the form. Note: You won’t get a paper bond back. Instead, you will have an electronic account at the TreasuryDirect.gov website.