Could be necessary to change the wifi options in any case, like default accesspoint die or any other case.
A quick way to change the SSID is better than have to reupload the code just for change the wifi station settings

This is indeed possible, but only through the serial interface using the following command:
s?ssid=<SSID name>&passwd=<password>
The easiest way for sending commands via the serial interface is using the serial monitor of the Arduino IDE.