I'm not fully sure how to change language on the NX75-Z device. The manual says to change the language while installing the battery, but maybe I don't quite understand. If I take the battery out, there's no way to change the language, since the device is off. If I put in the battery, pressing the fire button fires up the device. At what stage of installing the battery is there the option to change language? Sorry for the confusion.
Firmware will display, then "EN CH" to choose the language.
@cegoca is correct. Here is the directions from the NX75 user manual.
Language Selection: Pressing the fire button while
installing the battery will bring up the firmware version
then you may select English and Chinese language.
Press “+” or “-” button to select, fire button to confirm.