utorrent link:http://www.utorrent.com/
daemon tools:http://www.disc-tools.com/download/daemon
game link:http://isohunt.com/torrent_details/280740325/Assassin%27s+Creed%3A+Brotherhood?tab=summary

instruction:
1.download and install utorrent.
2.download and install daemon tools.
3.go to game link and click download torrent..
4.after the download finished on utorrent,open the file using daemon tools
5.simply open the daemon tools and it will appears on toolbar.
6.right click on the daemon tools in toolbar and click mount image.
7.choose assasin creed file and mount.
8.now you can open file and install.
9.enjoy.

for more details,watch http://www.youtube.com/watch?v=WGwWD-tcPmg&feature=related