Trouble installing nif scripts (please help)

I’m trying to install the Nif Plugin to Blender 2.49b. All of the tutorials i’ve followed use the 2.5.9 version, but the only one i can find is the 2.6.0 version, and it doesn’t have a .exe to run? Here is a picture of the folder.

Basically, can anyone tell me how to install the nif plugin to blender 2.49b?

Edit: Also another thing to note, i saw somewhere that you need to “run the .bat file”(https://forums.nexusmods.com/index.php?/topic/5161560-blender-nif-scripts-help/) but i couldn’t find a .bat file anywhere in the folder?