Why would you need to change any settings?
The only difference so far as the esc is concerned is that it 'sees' the 4 pole motor as spinning twice as fast due to the extra 2 poles on the rotor, so the total rpm limit you can achieve with 4 pole motors is half that which you can achieve with a 2 pole motor.
Same as a 2 stroke engine vs 4 stroke again; both engines of a similar size will move your motorbike just as well, but the 4 stroke will produce more torque and make a nicer rumble when you open it up, vs the 2 stroke which sounds like a bee in a tin...
You need to look at some pictures of the insides of a 2 pole & 4 pole motor of the same size to appreciate the physical differences ( and understand why you cant swap rotors ), but they still work in the same way when powered by a suitable esc.
Have a gander at this:
4 pole rotor & slotted stator
2 pole slotless stator
The rotor on a 2 pole motor is usually a solid long, round magnet with the shaft running through it. The rotor on a 4 pole is made of 4 separate magnets fixed around the shaft & wrapped in kevlar or carbonfibre usually- the stator is designed to work with a certain type of rotor so changing it could cause it to not work properly, or not work at all.
2 pole
4 pole
By all means try it though, just make a video so we can all watch what happens....