mac Replacement Custom wallpaper:
The first step: Right-click on the desktop, and then choose to change the desktop background, as shown in the following figure.
Step Two: Select the desktop background below the directory that is already included in the system, which is the wallpaper you see.
The third step: You can also choose the way to fill the screen, which is similar to Windows.
Step Fourth: Increase your own directory of wallpaper. Click the following steps to add a directory to see your wallpaper, and then select the wallpaper you added, the desktop background will be updated immediately.
Mac Replacement system default wallpaper:
1. Open the top Finder menu bar on the desktop,-[go to]-dropdown select-[go to Folder]
Of course, you can also open the Finder and press "Command + Shift + G" directly.
2. Copy "/library/desktop pictures/" to the empty space below the folder-click [Go]
3. See the Open Desktop Pictures this folder?
This folder contains all of the system's wallpapers, and we can replace the picture in that folder as the system's default wallpaper.
Note: Because it is a system file, when you add or remove wallpaper, you will be asked to enter the administrator password Oh.