Processing Chitosan from Crab Shell

I am trying to extract chitosan from crab shell (Japanese snow crab). I want to dissolve chitosan in water and mix in gelatin to obtain some type of gel, that I would then test for my Master 2 Architecture thesis. However, because I am from an architecture background I am having a hard time to understand the process of chitosan extraction.

I got 1M $\ce{HCl}$ (500 mL) and 1N $\ce{NaOH}$ (500 mL). We gathered around 3 kg of crab shell. I am following the guide of two researchers (here and here), but I can't really understand what they mean in terms of percentage, and dosage of the acid.