Toyota Connectors, disassembly?
 

I have looked and found one thread where it is mentioned to press down the small black tab inside the connector to pull out the original wire. But this does not seem to work for me.

Has anyone done this? I prefer not to have any splices in my wires that I do not have to have. So I want to replace the factory wires that goes into my toyota cop connector.

If you plan on pulling the wires out of the connectors then I'm assuming you have new pins to replace them with. Just look at the new ones and you should be able to figure out how they lock in, and what you need to do to get them out.

No I intend on reusing the pins. I have done this in the past on several other electrical connectors. It usually just requires minimal adjusting with needle nose pliers. After you re-solder the wire that is of coarse.