Many user ask us this question because they are not familiar / never use GitHub before. You doesn’t need any other tool or client program to download the code in GitHub. Since user script usually available in a single file, it is easy enough to just go and download that single file or direct copy in text form from there.

First go to the repository you are interested. Look for .user.js file. Click on it to open.

Then

• Use the raw button to download the file to your local disk,
• Or use the edit button to open into edit mode, so you can easily select all (Ctrl+A) and copy (Ctrl+C) from there.

Done.