I suck at linux, but it looks like it goes up until the line:

#Create a couple of useful 'binaries', /bin/rwp and /bin/rop. Guess what they do.

Everything before that appears to be the setup stuff. But from Genixia's comments if you already have the preinit.d directory created then it will skip building the scripts. I would just say try running the script since you already have preinit installed. I used the script before I installed preinit, and it worked great. But warning.. I am no linux freak.... I could be totally wrong... but thats my .02