Make sure your static strap is connected before you start working on the chassis. First, if you take a look at the chassis (photo 9). This is the heart and brains of your iMac. The CD-ROM is the silver box in the front and the mother board with the processor and ram chips (under the silver cage) are in the back. Try not to touch the circuits on the mother board, it reduces the chance of static. The hard drive is underneath the CD-ROM so you will need to work only on the front of the chassis. Have a piece of paper or small cloth handy to put on top of the mother board for protection. You will see why later.

1. The first thing is to remove the CD-ROM. It is quite easy to do but you want to pay close attention to what you are doing because it will make it much easier when you go to reassemble it. The CD - ROM is held in place by a spring. What you need to do is to is raise up the front of the chassis and with your thumbs push back on the front of the CD-ROM until the two small tabs (photo 10) have cleared their slots, then push up on the CD-ROM and it should raise up like in photo 11. When you have it raised it up a bit, look inside and you will see a silver retaining spring that should be hooked on a small grey tab (photo 11) on the bottom of the CD-ROM. Take note of how the spring hooks on to the tab. If the spring has already popped off, don't worry, you should still be able to see how the grey tab will clip on to the silver spring when you need to reassemble. Continue lifting the CD-ROM out. Put a piece of paper or cloth down on top of the chassis and lay the CD-ROM on top of it (photo 12). Careful not to pull on the wires connected to the back of the CD-ROM. You can unplug the CD-ROM if you wish but it is not necessary.

2. With the CD-Rom out of the way you will be looking at the top of the hard drive with the spring on top of it. Remove the spring from its slots and place it to one side (photo 13). Gently lift up the chassis (hold on to the CD-ROM) and look at the bottom side. Notice the two small tabs (photo 14), they hold the back end of the hard drive in place. Do not tamper with these tabs, just take note of their position, you will need to look at them in the next step.

3. This next step is a little tricky and it might take a couple of tries to accomplish but don't worry, it's really quite simple. Locate the two screws on either side of the of the chassis frame (photo 15), these hold the hard drive bracket to the chassis. Remove those two screws. Looking down onto the top of the hard drive, you'll see two holes towards the front on either side (photo 16). Insert your screwdriver into one of the holes and pry up on the hard drive bracket until the tabs (where the two screws were located), have cleared the chassis frame and hold it there for a moment (bracket & hard drive will lift together). Take your flashlight and look down inside between the side of the hard drive bracket and the chassis. In the back you will see the two tabs that hold the back of the hard drive to the bottom of the chassis. These are the same two tabs you saw in the previous step. What you need to do is, push the hard drive bracket back into the chassis just a bit until the small tabs in the back have cleared their slots, then continue lifting it up and out. Flip it over as you take it out (photo 17), just like you did with the CD-ROM, and place it down on top of the CD-ROM. Click for more photos of this last step.

4. There are two cables attached to the end of the hard drive. A smaller one with a yellow plug and a larger with one with a black plug and white tag. Disconnect the smaller cable by pulling on the yellow plug, it should come out easily. Disconnect the large white cable by holding the hard drive firmly with one hand and pulling on the white tag (photo 18) that is attached to the plug. Don't pull too hard. If it resists, try pulling moderately on each end of the white tag to see if you can coax it out a bit at a time.

5. Now that you have the hard drive out, you need to remove the metallic bracket. There are four screws, two on each side (photo 19), remove all four. Then lift the hard drive out of the bracket (photo 20). Hold the hard rive by the edges whenever possible and try not to touch the circuit board on the bottom side.

Congratulations. You have removed your old hard drive and are now ready to start reassembling.