Start by identifying the different parts of the dash surrounding the radio. The look for ways they are attached. Most pieces either snap in or are screwed in. Try prying the pieces gently (if it doesnt come leave it!). Eventually youll reach the radio, unscrew it from the brackets and but the new one in.
Sorry I cant help you more, but I have B12. To remove the radio from mine all i have to do if reach around the center consol and push...
-Nick