Step 1: Download the compressed folder.

Step 2: Extract the compressed folder (Recommended in an external hard drive).

Step 3: Open your Team Fortress 2 game folder by going to Steam, clicking the gear icon, hovering your cursor pointer to Manage and then click Browse local files

Step 4: Now go back to the extracted folder and go to the folder maps

Step 5: Go back to the Team Fortress 2 game folder by also going to the folder tf > maps.

Step 6: Once you have found the maps folder, copy the maps from the extracted folder to the maps folder from the Team Fortress 2 game folder.

Step 7: Once you have copied it, test it out by launching Team Fortress 2.

Step 8: After booting up Team Fortress 2, go to Create Server, and click on the tab for finding maps, scroll down until you find the custom maps.

Step Final: Once you have chosen the map, click Create and enjoy.