For Windows
Click on the correct resolution underneath the image that you wish to download.
Once the image finishes loading, right-click on the full-size image and select "Set As Wallpaper" or "Set As Background" from the pop-up menu that will appear.

For Mac
Click on the correct resolution underneath the image you wish to download.
Once the image finishes loading, right-click on the full-size image and select "Set As Wallpaper" or "Set As Background" from the pop-up menu that will appear.

Go to your Desktop Pictures control panel and click on "Select Picture" and choose the image. Please note that if you already have a picture, you must click on "Remove Picture" first and then "Select Picture".

Click on "Set Desktop" and close your control panel.