How to install Boot Camp on 32bit Windows 8 on a 2011 MacBook Pro?

I used Boot Camp to install Windows 8 Consumer Preview as the 2nd OS on my 2011 MacBook Pro. However after the installation I cannot install the additional Boot Camp just the drivers for webcam/wifi/ethernet/cardreader/display/chipset etc.

But I would like to be able to use the function keys to adjust the brightness and volume like on a normal laptop without having to go through settings.

Anyone know how?