Take just one battery out. Hold down the fire button. While holding the fire button down insert the second battery.
The screen will first display the "sigelei" logo, and keep holding until it displays "YH SX330 v1.2".
Btw, I learned this from FT forum and took no credit for it. While it's full of trolls, it also has some really knowledgeable posters. They can look at some pictures and figure a lot of things out.
That's exactly what my 100W+ shows when I follow your instructions. Thank you for the information. By the way, my 100W+ is about 3 weeks old, so I can not tell you what the earlier versions will read.