Do not open your computer or attempt any repair before reading and understanding the "Important safety information" in the ThinkCentre Safety and Warranty Guide that came with your computer. To obtain a copy of the ThinkCentre Safety and Warranty Guide, go to:http://www.lenovo.com/support
This section provides instructions on how to open the computer cover.
Turn off the computer and wait three to five minutes to let the computer cool before removing the computer cover.
To open the computer cover, do the following:
Remove all media from the drives. Then, turn off all attached devices and the computer.
Disconnect all power cords from electrical outlets.