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These two tabs, located next to the power plug, will probably need to be popped at the same time (they can be done one at a time but this is more difficult). This is when you will want to take advantage of the second small screwdriver. Using both of these or the case opening tool, pop the tabs and start to pry the shell open. At the other end of that side, you will see five more of these tabs. Pop them one at a time, keeping constant pressure as you open the shell, or use the case tool to open them all at once. Flip the 360 around to look at the front end, find the clip at the end near the DVD drive. This can be easily opened with your fingernail or a flathead screwdriver and a good deal of prying. There should be four tabs on this side, which you can take one at a time. With the shell removed, you should be able to see the inner casing now. Open this by unscrewing the cover panel. Flip the Xbox onto the opposite side and pull off the remaining shell to reveal the inner components.

Summary:
Open the two hole tab section. Open the five hole tab section. Ease open the shell. Unscrew the inner casing.