Download the mod then extract everything inside the games installation folder. And run the game and you should see all the Mortal Kombat Komplete Edition PC Boss kharacters has been added to the selection screen beside the DLC kharacters. Please make sure to make a backup of the original files so if anything goes wrong you can restore the original files.
After installing this mod, if you select Shao Kahn in the “Fatality Tutorial” mode the game will throw you back to the character select menu right after the “Fatality Tutorial” has been loaded. (founded by Berzerk)