Optimus 120-1995 - Manual (Page 5)

After you connect the speakers, power wires, and antenna, turn on your
vehicle's ignition and test the stereo to be sure it works.
If the stereo does not work, immediately unplug the harness. Recheck
your connections or have a professional automotive audio installer
complete the installation.
If the stereo works, disconnect the cable from the vehicle battery's
negative terminal and continue with installation.
MOUNTING THE STEREO
IF your vehicle does not have a prepared opening for a flat face (DIN E)
component, you must use an in-dash installation kit. Installation kits
for many local Radio Shack store.
If you use an in-dash installation kit, follow its supplied instructions
to mount the mounting sleeve.
If you are using an in-dash installation kit, follow these steps to mount
the stereo.
1. Disconnect the cable from the vehicle battery's negative (-) terminal.
2. Temporarily disconnect the wiring harness and antenna.
3. Insert the mounting sleeve into the dash opening and secure it by
bending the locking tabs out with a screwdriver.
4. Reconnect the wiring harness and antenna through the sleeve.
5. Slide the stereo into the sleeve until it locks into place.
Note: To further secure the stereo and ensure proper electrical
grounding, attach the supplied hex bolt to the back of the stereo.
Attach one end of the supplied metal strap to the bolt and the other
end to an existing bolt on a solid metal part of the vehicle.
6. Reconnect your vehicle battery's negative cable.
REMOVING THE STEREO FROM THE DASH
1. Disconnect the negative (-) cable from your vehicle's battery.