[header] How to install a car stereo [title] Set the parking brake and disconnect the negative cable from your car battery. [step] Be sure to do this to avoid short-circuiting the electrical system during the installation. [substeps] For instructions on disconnecting the battery, see how to disconnect a car battery. 
[title] Unscrew any screws that are securing the trim in place. [step] Be careful to remove all screws before trying to pry off the trim or you may break it.