Turn the Xbox 360 upside down to remove the faceplate
Pry the faceplate off with both of your thumbs
For the next steps I'll be using the Xbox 360 Unlock Tool Kit
The bottom vent is held on with 6 plastic release tabs, 3 on each side.
Gently pull the vent back as you push in the plastic tabs with the point of the unlock tool
Rotate the Xbox 360 so the unit sits upright (hard drive up)
You must remove this rubber foot to access this plastic release tab
Insert the 360 unlock tool into the square opening (chose either left & right side) in the top vent to access the plastic release tab and pull the vent upward.
Release the middle tab by pushing it with the Unlock Tool. You may have to push the tabs on both sides.
The back of the 360 is where the unlock tool really helps open it's shell.
It works with both A/V & HDMI versions of the Xbox 360
Like a key, match the unlock tool's 5 pins to the 5 release tabs in the back, then push in the tabs
Keep the shell spread open with one hand, while you release the 2 release tabs on the other side.
Like a key, match the unlock tool's 2 pins to the 2 release tabs. You should now have the rear of the shell open.
Once the rear is open, looking at the front, starting at the Eject button, there is 4 release tabs
You can use the corner of the unlock tool to pry open the release tabs
6x size 10 torx screws hold on the top of the 360 shell. Use the T10 side of the Torx wrench to remove these screws
You can either remove the Eject button, or lift to clear the top shell when removing it.