1. Get the main body of your iMac and put it face down on your table. Don't forget to put a towel or soft cloth down to protect your iMacs screen. Push the four cables as far as you can to each side.

2. Pick up the chassis with the plastic handle and turn it over so that the silver side is facing you then lower it straight down into the body of the computer (photo 21). Note: As you are lowering it down into the computer, make sure the cables on the side don't interfere with it as you are lowering it down. Also, make sure the two guides, one on each side of the chassis (photo 21), go down on the inside of the plastic body. Once you think it is down all the way carefully tilt the entire computer back a bit and see if the front of the CD-ROM tray is flush with the front of the computer. If it is, you should then be able to put the two screws that hold the chassis to the body of the computer back in (photo 22).

3. Plug the four cables back into their appropriate spots. The two on the left first then the other two. Make sure to put the cables in their anchors and to replace the screws (photos 23).

4. Replace the plastic cover on the bottom by lowering it straight down over the chassis until the bottom is in place then push forward on the top end of the cover to snap it into place (photo 24). Replace the screw that holds the cover on. The hole is under the handle.

5. Carefully turn your iMac over into its upright position and reconnect the power, keyboard and mouse cables as well as any other cables like internet or speakers.