One can make this more complicated than it really is. If you don't have memory mirrors(and with 4 wires, I don't think you do), then there are two motors in the mirror-one for up/down and one for left/right. You can see them in the first of those great pictures above. If you don't have the wiring diagram , use an ohmmeter to pair up the leads. The switch circuitry does the reversing of polarity required for the left/right or up/down operation. Let us know how the wires pair up and we can go from there. We might mix up all the functions but once the motors and colors are identified, simply re-connect and you're done. I've done this several times and almost everyone tries to make it too complicated.

Paul