Take the whole external casing off. Pull out any plastic activity lights and, rip off any intel inside stickers. Wash the case down with windex and than water, wait until it is dry to start painting.
Do not paint in the sunlight.
Do not over do it. You will be left will sh!tty looking blotches and bubbles.
Go over it with a light mist. With a nice back and forth motion. Repeat until it looks good.
Let it dry for 20 minutes.
Get a can of Clear enamel and go over it with a light mist, a couple of times.
After that let it dry for 1 hour. The paint will not fully cure for 4 days.