I just got done replacing the LCD screen on my uncles SD300 camera using the instruction provided by this kind gentleman:
I also took some pics of the process. If anyone would like to see them, email me at mannyz at pacbell.net The written guide worked great but I think it's nice to see some pics as well to know what you're getting into. You need to have good eyesight as this is very intricate work
One tip I would like to add is if you fold a piece of scotch tape in half (with a lil sticky left at the end) you can feed it through the crack first and use it to pull the LCD cable through behind it.