Here are the instructions I followed - all done at your own risk.
http://chdk.wikia.com/wiki/CHDK_quick_install_Guide
Live Histogram doesn't show up well on the vid - the colours can be changed in the settings.
You have to press & hold the power button until the camera comes on with this mod, the same with the play button for reviewing your images.
Press 'play' then 'OK' for menu 1 (scripts etc)
Press 'play' then 'menu' menu 2 - further options & customs
I forgot to mention the on screen display items such as battery % remaining, time etc.
Also you can save in DNG format.
Enjoy :)
