To change the network settings on a device, you will be able to navigate back to the settings on the device i.e. either use the back button on the remote, or double-right click on a USB mouse plugged into the device. 

Once navigated to the settings page, please select the Apps option and choose MXQ Settings from the list.  From there, you will be able to reset the Wi-Fi settings as usual. 

If you require more information re: setting up your device please see the following link: https://www.signstix.com/support/tutorials/preparing-a-signage-device/