My answer is not necessarily for the connector you are referring to but to connectors in general that I have worked with for over 30 years. The metal insert is inserted from the side of the wire. It has flexible spring clips that when they are inserted into the hole they will compress to allow them to be inserted. Once inserted far enough the flexible spring clips will pop back to their original position. To release the metal insert you need to insert something very small into the other end (without wire) and depress the spring clips and push back out toward the wire end. I have a removal tool somewhere for one size of molex connector that fits most molex connectors sold by Radio Shack. It only works with one size. I was hoping to find a picture of an uninserted pin to show but I was not able to.
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