How To Play Singleplayer Maps in Co Op

1. First of all, you will need to download some files into portal 2. But that only goes for the host, your friend or stranger wont need to download it unless they are the host (atlas). Download the Zip File Portal2 Single-Player in Co-op.zip - Google Drive

2. After you have downloaded the .zip file, you will see a folder named "maps" in there.

Open Windows Explorer and go to "Program Files (x86)\Steam\steamapps\common\Portal 2".

When there, you should see a bunch of folders. There should be a folder named "portal2", drag the "maps" folder from the .zip file into the folder "portal2".

3. You are almost done! Now start Portal 2.

Go to Co-op and start a game with your friend or stranger.

When you see the animation or the robot blueprint .gif along with steam sounds you have to open the console.

In the console type "commentary 1", then to enter a map, type "changelevel mapname" for example, changelevel sp_a2_bts1.