Ok here ya go,

 Open My Computer then goto c: then program files then Atari then DeerHunter2005 Then Game.

it will look like this 

C:programfiles/atari/deerhunter2005/game

in the game folder Creat a folder that says  CustomLevels  just as u see it here....

then download the maps and save into that folder...CustomLevels


Thats it and then you can play custom maps..


   Any questions just email me......thanks Dan....aka SpiDeR