Trully the easy way from what I know is to go to a junk yard and get the whole rear multi link beam set up off a 200SX SE-R or Sentra SE if there is one there. If you do that it will be fairly straight forward giving you all you need. Coarse that will take some wrenching on your part. I also hear the Greg from Gspec sells some sort of conversion from fast brakes. As far as a step by step guide I dont know of one. Hope that helps some.
EDIT
Just realized we were talking about a B13 not B14. This one is up for someone else. Sorry