How to obtain the initial guess for Maximum likelihood estimation

Hey, I am using Reis (2009) model, and I just replicate his results using his data. I attached his codes, my question is about the initial guess (X0) in the code of SIGE_mode, when I will try to use my own data I have to change these initial guesses. This vector will define the mode so it is a crucial to know how to get it. Thanks in advance. Houda