Click the green "Subscribe" button on the map page. Steam will then download the map to your game and you will be able to access it from open/local games. There's a button to switch between mods/custom maps and stock content but I forgot its name, It should be at the top of the list of maps, if it doesn't put you onto the mod/custom maps list by default.

thanks

hi

hi

thanks

this is helpfull

you hit the subscribe button