My first recommendation would be to keep the laptop in a place where the fan can be ventilated. If the laptop is being used on your lap then this may prevent the fan from circulating cool air into the interior of the laptop, therefore cooling it down. If this does not seem to work then the fan and/or heat sink my need to be replaced. Both of these can be replaced to prevent overheating in the laptop.

Well, it is unlikely your power button will break from dropping your laptop. However, if your power button is to break, it can be replaced. You can replace it by first removing the keyboard plate cover. You will need to remove the screws from the bottom of the laptop and pry to the back cover from the laptop. You will then need to locate the power button on the underside of the keyboard plate cover, it should be in the upper left corner. After removing the power button you can replace it and put it back together. The laptop's power button should function correctly now.

Remove the spacer and then insert a CD disk drive into the hole left by the spacer.