A program replacing method and apparatus replaces a program in a broadcast receiving terminal apparatus. A first program is registered so that message transmission is enabled between the first program and a POD (Point of Deployment), the first program having an identifier identifying a program type of the first program. If a second program exists in a broadcast receiving terminal apparatus, the second program is notified that message transmission between the second program and the POD is to be terminated. The method receives approval for terminating the message transmission between the second program and the POD, from the second program, terminates the message transmission between the second program and the POD, and notifies the first program that message transmission between the first program and the POD has been enabled.