Installing and Playing BO1 Custom Maps
1) Download the mod launcher.
The mod launcher for BO1 will add a "mod" category to the BO1 menu. This is a rar file named game_mod.rar. Or download below.
Current version is 1.3.2
2) Install the mod launcher.
After it's finished downloading open it and extract everything, in the game_mod.rar, into your Call of Duty Black Ops folder. This is usually located in your SteamLibrary\steamapps\common\Call of Duty Black Ops. In Steam you can also find where Black Ops is installed by going to your LIBRARY, right click on Call of Duty: Black Ops, going to manage and and click "Browse local files:.
3) Make a folder named "mods".
In your Bo1 directory create a folder and name it "mods". This is where your custom maps will installed.
4) Download your custom map.
Once the map is finished downloading Open and extract the folder to the mods folder you created earlier.
5) Start BO1 using BO_Mods.bat.
In order to play custom maps you must launch BO1 using BO_Mods.bat located in the Call of Duty Black Ops folder (Note: Steam must be running). Do not launch BlackOps using Steam or the BlackOps.exe. The map will only work using BO_Mods.bat.
6) Loading Your map.
Now in the BlackOps menu you will have a "MODS" category, click that and select the custom map you want to play. Once it loads click on Zombies choose custom zombies and click on the map name to start playing.