How do you use infrared light with the DIY Public Lab Spectrometer 3.0?

I want to make a spectrometer that can detect what type of food is being held in front of it.

There are a few things I know already. To start with, the spectrometer cannot properly detect the food with just visible light, since the light doesn't reflect off the food with enough strength. That's why I wanted to try using infrared light since it passes through the food and can give an accurate depiction. However, it seems like the spectrometer in the Public Lab Spectrometer 3.0 Kit has an infrared filter. I'm not sure how to remove this. Does anyone know how to remove this filter and/or make the spectrometer work in some other way? Also, if anyone has actually used this spectrometer with solids before, do you know any other challenges that you faced with or without the infrared? Did you use the spectrometer in the same way?

Thank you to anyone who can help! Hari.