This guide will tell you how to install custom game modes and maps for Call Of Duty BO3. Go through the guide and follow the simple steps to do so.
First, you have to open Steam and select the Community tab from the top. After that, go to Steam workshop, select the game, and then select the modes you want to download for the game.
After this, you have to boot up the game and then go to the MOD tab. Select the mod you have just installed and then click on the Load button to load up this custom game mod.