2 VERY helpful bits of info I learned before I put a winch on my M35A2C..
First, Put a piece of plywood on the radiator so you dont put the winch thru it when your setting it in place... Failure to do so could cost you a new radiator.
Second. Dont tighten up all the bolts on the extensions brackets, winch, or bumper until it is ALL in place. Failure to do so will cause one side to be 1/64th of an inch off from the other, and things wont line up straight, causing you to have to loosen up the bolts.
Drain the tranny before you take the cover plate off... If you dont, enjoy the 90W oil bath...
This topic has been covered several times on here. search for it. There are more helpful hints, but these are the major ones..
Here is a pic of all the parts, including the often forgotten bolt sleeves that go on the bumper..
http://www.steelsoldiers.com/deuce/42484-got-my-winch.html