After downloading the map right click on it and choose "Extract All". Then click "Browse". You'll then be prompted for a location, and if you paste in "%APPDATA%\.minecraft\saves" and press enter. Finally press Select Folder.
This will end up extracting the files to something like C:\Users\<user name>\AppData\Roaming\.minecraft\saves. You can also get to this location by pasting "%APPDATA%\.minecraft\saves" into an address bar in explorer (without the quotes).
After downloading the map right click on it and choose "Extract All". Then click "Browse". You'll then be prompted for a location, and if you paste in "%localappdata%\Packages\Microsoft.MinecraftUWP_8wekyb3d8bbwe\LocalState\games\com.mojang" and press enter. Finally press Select Folder.
This will end up extracting the files to something like C:\Users\<user name>\AppData\Roaming\.minecraft\saves. You can also get to this location by pasting "%localappdata%\Packages\Microsoft.MinecraftUWP_8wekyb3d8bbwe\LocalState\games\com.mojang" into an address bar in explorer (without the quotes).
On Mac OS/X your saved games are at: /Users/<username>/Library/Application Support/minecraft/saves
You can get there by pasting "~/Library/Application Support/minecraft/saves" into the Spotlight search window.
Just extract the downloaded ZIP file to that location.