To change from I Bonds to EE Bonds, follow the above steps using the I Bond enrollment form to cancel I Bonds and the EE Bond enrollment form to sign up for EE Bonds. You cannot have your existing EE Bonds reissued as I Bonds or vice versa, or exchange bonds of one series for bonds of the other. First, check with your employer to be sure they offer both series and that their payroll system allows more than one bond. Ask how you should submit the request. For many employers, you can simply submit a new enrollment form as in question 2.1 above.
Some employers accumulate allotments for all of an employee's bonds at the same time.
Other employers issue the bonds in rotation. Ask your payroll department how your added enrollment will affect the amount of your allotment and the issue dates of your bonds. Fill in the inscription information giving your name and address. Submit the signed completed form to your payroll department. There is no need to change the address on savings bonds you have already received.