just insert everything in this directory into your half life "valve" folder. if you don't know where that is follow these steps

1. select half life on steam, right click and select "Properties"
2. navigate to "Installed Files" then click "Browse..."
3. in that folder should be the "valve" folder

after that, just load the game, open the developer console, and type "map storage" without the quotes.

enjoy the map. see if you can find the secrets!