just put both cars in the PCE slot connect them up to your powersupply, and put the crossfire bridge on, you only need one by the looks of it. the drivers will see it and ask if you want to enable it. than your good to go, make sure you got a good powersupply through.
I should have typed my first one like it I just couldn't be assed at the time LOL, trying to look like a "enthuiast"
its not working through ;D