I was vague on purpose...
In /storage/.cache/connman you do see a directory for every configured wifi network as "wifi_SSID_MAC". The configuration is stored in the settings file.
Changing i.e. password is simple but if changing the SSID a new directory has to be created.
Important: if changing from the running system connman has to be stopped before.
You should test every step in your environment with your identical box before.