I see documentation on how to clean the sensor and internal surface of the AR window for every camera other than the ASI1600GT. Is there a documented procedure for getting inside the AR window to clean it?
You can follow the document to clean both sides of the AR glass.
https://astronomy-imaging-camera.com/manuals/How_to_clean_ASI_camera_and_redry_the_desiccant.pdf
My main need is the instructions on how to gain access to the inside surface of the ASI1600GT window.
You can follow the document to clean the ASI1600GT window.