You can reset the device by loading the reseteeprom.bin file located here:
And then loading 1.8 (or another version).
The AP mode is a little dangerous to use because if it fails to connect to your WIFI, or your WIFI details change then the device will not be able to be contacted. In this case it will automatically re-enable AP mode. So if you loose contact with your device you can either stop your router or power up the device where it is out of reach of your WIFI and it will re-enable AP mode. Or use the reseteprom.bin file to reset the device back to factory settings.