First and foremost, be sure to unplug both power and AV/S-Video cables and remove any games that may be plugged into the console.

In order to get into the system you're going to have to remove the 4 rubber boots on the bottom of the console in order to access 4 hidden screws underneath. The other two screws are already accessible.

These rubber boots are cheap and not easily reusable if they become stuck to each other or other items. I completely removed mine and because they weren't reattached right away they became stuck to each other and trying to pull them apart causes them to rip. In my case, I'm not particularly concerned if they are there or not and replacements

shouldn't be hard to find online I'd imagine.

If you'd like to avoid removing the boots utilize the picture provided to simply poke your screw driver threw the boot where the screw would be located. It might be tricky as you're looking for the only circle surrounded by several squares.