You will need:
1x Phillips Head screw driver
1. Start by removing the left side panel from the chassis.
2. Disconnect the top fan from your motherboard or power supply.
3. Locate and remove the two screws that secure the top panel to the chassis. You will note that one of these screws may have a ground wire attached to it. This ground wire is attached to the front port assembly.
4. Locate and depress the four clips that hold the rear and middle section of the top panel to the chassis. As you depress each clip, lift the panel gently so that the clips remain unsecured. Please be careful at this stage as there are two more clips at the front of the chassis that will be handled in step 5.
6. To release the front clips: grip the top panel as close to the front of the chassis as possible and pull directly upward. You want the force exerted on the top panel to be as close to perpendicular to the chassis as possible. Note: if you still have the front ports, power, reset, and LEDs hooked up you should proceed with caution so as not to damage anything.
7. Flip the top panel 180 degrees. Once again note that if you still have the front ports, power, reset, and LEDs hooked up, you should proceed with caution so as not to damage anything.
8. Locate and remove the three screws that secure the fan to the top panel.
9. Simultaneously pull up on the section of the fan that is closest to the front while pulling on two corresponding clips.
10. Lift the rest of the fan away from the top panel. Note: there are two rear clips used to hold the fan, so you will want to lift the fan towards the front of the top panel to avoid getting snagged on them.
11. Place the new fan onto the top panel. The Antec logo should be on the same side as the fan grill. Press down so that the fan is secured by the four plastic clips mentioned in steps 9 and 10.
12. Secure the fan further by reattaching the three screws from step 8.
13. Flip the top panel back over.
14. Replace the panel on top of the chassis starting with the front clips and working your way back.
15. Secure the top panel with the screws from step 3 . Be sure to attach the ground wire coming off the front port assembly to one of these screws.
16. Plug the top fan back into your motherboard or power supply [and reconnect any other cables you may have disconnected].
17. Reattach the left side panel to the chassis.