code_fibercoll.pro is used to divide the mock galaxies into different populations (collided and decollided sets) as detailed in Guo et al. (2012). It's written in IDL and requires the idlutils package.
                                  
To suitably implement the fiber collision effects in SDSS on the realistic mock galaxy catalogs that applies the mask of the observed galaxy sample, we would need the tiling information of each galaxy, i.e. the number of plates (or tiles) covering each galaxy. code_mock_generate.pro is the code for applying the fiber collision effects in a mock catalog.

These codes are all self-explanatory, with lots of annotations. If you have any further questions, feel free to contact me.