First off you get a small flathead screw driver and you pry up the plate to the outside of your shifter. Then you use that same screw driver to pry out above the a/c vent holes, but don't pull to hard they will break then go below the clock and pry that piece up it should come up with the a/c vents its one piece. Then pry out the piece surrounding the stock unit. there will be screws in one of the corners so be careful to see which one it is. After that you will need to pry the ash tray on the right side with the screw driver, and then get a Philips head and unscrew the screw holding it together. Then unscrew the 4 screws that are gold around the radio then your done.
take it to a front end shop you cant do it your self
Begin by removing the decorative cover from your 1990 Chevy Caprice factory radio. Remove the radio retaining screws. Remove the wiring harness and the antenna cable from the back of the radio.
Chainsaw?
take radio out and look to left of radio
Take the radio out of the dashboard, the code is on the side of the radio.
If you take your car to Nissan car dealership and request for your radio code with the right identification, your wish will be granted.
87 or 89 is what the factory says to use.
5W30 weight is factory specs.
Get an Allen wrench and take off the plastic cover on the top of the motor and they are all under there..
hit it with a baseball bat or a sleige hammer
to make it easier go to any bestbuy or frys electronics and get the harness for the stereo and jus match the colors and you ready to go also you might need the installing kit but, if the maxima has premium sound you're gonna have a hard time to figure out the wires u need to connect it to. if it does also your sub won't work unless you take your time to find the wires from the factory amp which i wouldn't bother at all
* Disable the airbag system * Remove the center bezel panel from the dash and the plastic panel just below the ashtray * Remove the screws and pull the air conditioning controls/radio/Cd player assembly away from the dash * Disconnect the antenna lead and the electrical connectors then remove the screws at each side bracket to remove the radio or Cd player from the air conditioning controls/radio/Cd player assembly