WARNING: These additional steps are only for truly filthy membrane-type keyboards with sticking keys. Don't use these steps with laptops, or with mechanical keyboards (which have a spring under each key and can be identified by a distinctive click when you press down).
5. Keep track of the keys.
If extreme measures are necessary, access the keyboard's interior by popping off the keys. Before you begin, use a copy machine or a digital camera to record the layout of the assembled keyboard so you can return each key to its correct location.
6. Remove the keycaps.
Using a small screwdriver, carefully pry up each key. It should pop off easily. Do not remove the spacebar or large keys such as <Shift>, <Enter>, or <Tab>. Putting those back on can be difficult.
7. Go after the stubborn dirt.
Loosen and remove leftover particles using compressed air. Use a cloth dampened with the solution from Step 3 to remove dirt and stains. For stubborn stains, use cotton swabs dampened with 90 percent isopropyl alcohol. Then use the compressed air again.
8. Replace the keycaps.
Carefully snap each keycap back on. Make sure each one works freely as you proceed. Plug in the keyboard, and test all the keys when finished.