not really easy, you would need a tank that works as ours does, it is not simply reserve fluid and a hole to vent if it overheats the tank in our cars is part of the entire cooling system. our tank not only helps hot coolant expand and cool it also is part of the circulation of the coolant in the system, if you follow the hoses out of your tank, one runs to the radiator, the other runs to the upper radiator hose flange, this is how coolant circulates in and out of the tank we have a downward flow system so hot coolant enter the top of the radiator and gets cooled as it passes through exiting the bottom cooled and through the thermostat back to the engine well the tank is tied into this too. in the old protégés from 00-03 they had just an overflow tank that sat off to the right of the radiator and had 1 hose that ran to the radiator cap, this is a tank you can use just any old tank on, as the cap on the tank did nothing but keep the fluid in, and the hose to the tank was just there so if you overheated it could push out hot coolant and there was a vent tube on the tank that would push said hot coolant out and it just went on the ground, well the hose works to also allow the extra coolant to return as the cap closes and pulls vacuum when it has overheated or is otherwise low. in our cars there is not a "radiator" cap as the radiator is sealed and has no cap on it anywhere. the radiator cap on our cars is on the tank. this tank works different in the fact that it will allow hot coolant to expand and fill the tank, then if needed let hot coolant out without letting in air. this is why max is below the top so there is expansion room in the system should you overheat. well this tank also plays a part when not over heating as it is part of coolant flow in the system, and has the cap that holds the pressure in the system. so it is not easy to use a different tank in the 3. you must get a tank that will hold a radiator cap with 21psi and has enough expansion room if you overheat as well as allowing coolant to circulate in the system properly, as our tank does.
yeah you need to make sure it can function as an expansion and return tank and hold the pressurized radiator cap. if corksport where to release one it should be a perfect replacement, and will probably use the factory mounting spot, since corksport is mazda aftermarket specialized. our tank is more than just a tank.