How to replace the win7 theme?

I often stare at win7's default theme for a long time, and it doesn't make sense. Today I deliberately read how to replace the win7 theme post. It feels quite simple to replace. And it is the official recommendation. It is recommended that you do not need to use any cracking tools, etc., which will damage the system files, resulting in a very unstable system.
Tools/Materials
A Windows 7 system that can be networked
Steps/methods
Click on the desktop right button and select "Personalize", pop up the following window:

Click In the above picture, “Get more topics online” will open the official Microsoft theme website. As shown below:

Here, I chose the theme of "Sapling", click to download the theme. And stored in the computer.
After downloading, double-click to run the downloaded file. The system will automatically replace the file.
Let's take a look at replacing the good theme. As shown below: