How to recompile libraries after changing source code

Hello all, I am currently undertaking a project and a requirement for that is to change part of the source code for an open-source program. I am quite new to using Geant4 and I found that after changing the source code the libraries must be recompiled but I don’t know how to do that so if anyone is able to shed any light on this topic, that would be very much appreciated.

Thank you

Please see the relevant section of the Installation Guide