code: def preprocess_files(self, prefix):
              
              if prefix is None: return
              files = ("bin/yang2dsdl", "man/man1/yang2dsdl.1",
                       "pyang/plugins/jsonxsl.py")
              regex = re.compile("^(.*)/usr/local(.*)$")
              for f in files:
                    inf = open(f)
                    cnt = inf.readlines()
                    inf.close()
                    ouf = open(f,"w")
                    for line in cnt:
                          mo = regex.search(line)
                          if mo is None:
                                ouf.write(line)
                          else:
                                ouf.write(mo.group(1) + prefix + mo.group(2) +
                                          "\n")
                    ouf.close()
docs: Change the installation prefix where necessary.