Installing the new hard drive and reassembling the computer is done in the exact reverse order as it was taken apart. Below, I have written out all the Reassembly steps and added some photos to guide you through the process.

1. Place your new hard drive into the metallic bracket and put the four screws back in. The connections end of the hard drive goes with the open end of the bracket, the same end that has the two little tabs (photo 21).

2. Note: In step 4 below, the two tabs (one on each side) on the end of the hard drive bracket (photo 21) will need to go into the two slots in the bottom of the chassis (photo 22). It is not difficult but it is helpful to know their locations before you start plugging in the cables.

3. Look at the two cables to be plugged into the hard drive. Notice that each plug has a locating notch. These must be lined up with their corresponding groves on the hard drive when you plug them in. Place the hard drive face down on top of the CD-ROM and plug in the two cables.

4. Pick up the hard drive and turn it over then lower the back end into the chassis but don't lower the front end in just yet. Look inside between the side of the hard drive and the inside of the chassis (photo 23) and see if you can see the tabs and slots that were pointed out in step 2 (a flashlight is helpful). See if you can get both tabs into their corresponding slots then lower the front of the hard drive into the chassis. Once it is in, you can lift up the entire chassis to see if the tabs went in properly. If they did, go ahead and put in the two screws that hold the hard drive bracket to the chassis (photo 24). If not, take the hard drive out and try again.

5. Replace the spring that goes on top of the hard drive. Make sure that the end of the spring is pointing up (photo 25).

6. Pick up the CD-ROM and note the position of the tab on the back end of the CD-ROM (photo 26). Flip the CD-ROM over and lower the back end into the chassis. As it goes in, you must get the tab on the end of the CD-ROM to hook the end of the spring below (photo 27). Once it hooks, continue to gently push the CD-ROM back into the chassis until the tabs on the front end of the CD-ROM (photo 28) have cleared the frame, then lower it down the rest of the way and let it come forward a bit to lock in place. Now, put the chassis to one side.

Note: It is now safe to remove your static strap.

7. 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 iMac's screen. Push the four cables as far as you can to each side.

8. 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 29). Note: Make sure the cables on the sides don't interfere with the chassis as you are lowering it down. Also, make sure the two guides, one on each side of the chassis (photo 29), 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 in the two screws that hold the chassis to the computer (photo 30).

9. 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 31).

10. 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 32). Replace the screw that holds the cover on. The hole is under the handle.

11. The upgrade procedure is now complete. Carefully turn your iMac over into its upright position and reconnect the power, keyboard and mouse cables. Don't turn the computer on until you are ready to do the Formatting & Partitioning procedure.