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](http://here) and [here](http://www.sciencedirect.com/science/article/pii/S1658077X16300224)), but I can't really understand what they mean in terms of percentage, and dosage of the acid. 


Could you please help me in very simple terms?  

What does the percentage relate to (solute and solvent)?  

Do I need to add water with the acid I have and then mix it with the shell?


