Installing new main router To existing network

I have a question hopefully someone can direct me down the correct path, presently I am running 4 AirPort Extreme 3 hard wire 1 wireless. I want to replace the main router connected to the modem with a brand new router, now once I set the new router up do I have to reset each other router or will they connect automatically, and if I do have to reset each one how do I go about doing it…..Thank You