I submitted my Federal return and it as accepted but I chose to pay what I owe in full but I would like to take the installments now. Can my return be changed?

No, I'm afraid not.  Your payment information was transmitted to the IRS when you filed the return and the IRS has it now.  Whatever payment arrangements you have made with them have already been entered into the IRS system.  You can try to contact the IRS to change your payment arrangements but contacting the IRS at this point can be very difficult.

Here's the contact information for the IRS.

@AJRios73