How do you remove an after market car stereo from a 91 Geo Prizm?

Remove the from dash panel over the stereo. The whole things snaps off from over the stereo to over the stearing column. Once you remove that, look on both sides of the stereo and you will see 4 screws, remove those, pull out the stereo and unplug it. Ohh, it is really helpful to unplug the lighter, ashtray and defroster, you will see that when you start taking the panel off. Pretty easy, now, if you can help me out with the stereo color codes, that would be sweet, lol.