Step 2: Locate the CD changer plug & Pins
Now here's where you have to do a bit of googling. Figure out what the pin layout is for your radio's CD changer. Try searching with something like "Honda Accord 1996 CD changer pinout" I was able to find this layout for an Acura which was close to my Honda for the basis of mine. Remember, there's only a couple car makers, so there's a lot of similar equipment out there across brands. Honda civic may be close to the Civic, and also close to an Acura. The same should apply for domestic cars.
The 3 pins you need are: