I'm not familiar with your particular windlass, but the following should apply:
I assume that the OEM setup was for UP only and that you have a simple solenoid switch to control it. I also think that the motor would be a two-wire connection and not a 3-wire. (Three wires would indicate a motor that is reversed without changing polarity to it.
What you would need to purchase is a reversing solenoid. This device is wired to the battery and to the windlass and will reverse the voltage to the windlass motor via the UP/DOWN switches or control. An UP/DOWN control (or two foot switches) would then be connected to the solenoid.
You need to check that the windlass can be reversed and that there is not some sort of mechanical limitation that would prohibit that operation.
This solenoid is about $150-200 and it would replace your existing solenoid.