Here are some photos from when I did mine. The first photo shows the pins and my completed Kenwood wire harness adaptor. (In hindsight, I should have separated the wire loom into two harnesses out to the plug.)
In the 2nd photo, you see the red wire lock retainer which needs to be pushed up and pulled out of the plug to release the pins. This plug is one of the adaptor plugs you buy to install the radio. Just make sure you CLEARLY mark the plug and write down exactly where the pins go back in.
The 3rd photo is, well... it's a photo showing you exactly what I told you to just do... but double check your own. This shows the pins removed. With the red lock pulled out, you will easily see a little tab that you push to one side to pull the pin out. Very easy to do, just don't bend it out so far that you break it.
Photo 4 shows an alternative to buying the new pins. IF you have one of those soldering jigs with alligator clips, you could open up your old pins where the insulated wire is crimped on. You will not be able to remove the stripped wire end, but you "can" solder the pins on top of where they are crimped. You must have that solder jig to do this. I have replaced many damaged wires from using the right pin from other plugs. The new pins make this job much better though so I am just giving you an option.