I've tried this and other many ways, but the problem is that my card it's no been recognized by the OSx. It recognize it on the boot, but when the system is loaded up, only the Intel HD graphics is active. I can disable the Intel HD on the BIOS, for what I've goggled there's no way of setting the Intel as discret.
With the intel I can do much, I cant even watch a video on youtube with this card. It sucks. I must install Windows 7, cause I work with photography and video and can't be without good VGA performance. A real shame because I loved Lion, this week as been so much fun playing with it.
A real shame.