Ok, I will give this a shot as I just loaded the CHDK hack onto my A630 and it was fairly straight forward.
Go to the CHDK Wiki link on the first page of the ScubaBoard Canon page. register with Wiki as a user.
Scroll down about half way down the Wiki page to where it reads Links than downloads under Download CHDK.
You will want to insert your memory card into the card reader on your comp at this point because you will be downloading the hack directly to it.
Read the info at the to of the downloads page. I went with the standard GrAnd's version and have no problems with it.
Click on the A630 v100.C Depending on your comp it will download to your computer and ask if you want to open or save the download. Choose save and the location of the memory card on your comp.
this is copied and pasted from the FAQ section linked hear
FAQ
Q. How do I get CHDK onto my camera's SD memory card?
A. Follow these steps:
* Remove the SD card from your camera and put it in the card reader of your PC.
* Extract the files from the firmware zip file that you have downloaded.
* Copy the files PS.fir and Diskboot.bin into the root folder of your SD card.
* If you are on a Mac, read and follow this link
* Put the SD card back into the camera.
or... (newbie way using Card Tricks, Windows only and up to 4GB cards)
* Remove the SD card from your camera and put it in the card reader of your PC.
* Download and install Card Tricks.
* Open the application and select the CARD's DRIVE, when asked. (pay attention: is the drive corresponding to the SD memory card!)
* Click the Format as FAT button, read and accepted the notice.
* Click the Make Bootable button, read and accepted the notice.
* Download the ZIP file with the CHDK version of your choice. If you don't know, just press the Download CHDK button and pick your camera model ZIP file. Just remember where you saved it!
* Click the CHDK binary button and point to the ZIP file you downloaded.
* Remove the card from the card reader.
* Lock the card! (this switch in the SD card)
* Your card is now autoload and ready to use.
* Place the write protected card back in camera and turn on. If everything went right the CHDK splash screen will blink.
Lower on the same FAQ page is a dyscription of how to load and use the new features.
Hope this helps??
cheers,
Brian D.