Your best bet is to use something like Bootcamp or Parallels, and just install Steam again on a Windows virtual machine on your Mac .
4 Answers · Games & Recreation · 16/08/2011
...insert windows cd install windows cd presto windows on a mac
2 Answers · Games & Recreation · 03/03/2014
Legally, nowhere. And there's no point to pirating it since it's free to play.
3 Answers · Games & Recreation · 06/09/2012