Since you mentioned the file is a .rar file, make sure you have a program like WinRAR or 7-Zip installed to extract the patch files. Once extracted, simply run the .exe or copy the files into your game directory to enjoy the improved experience!
: Allows players to track five species, including the European Roe and Axis deer. Installation & Safety Tips Deer Hunter 2005 The Season V1.3 Patch.rarl