switching SDK help needed

Hello,
I am using rayfire 1.6.1 and in 3DS MAX 2012 and am receiving an error that says “Switch to PhysX SDK 3.2”

I have downloaded the new SDK but do not know how to “switch to” it.

can anyone please help

thank you
Josh

You need to switch engines in control panel of PhysX plug-in, not download the SDK