First, download a small software called WinMPQ on the Internet. You can find it by going to Baidu! ~

Let me tell you how to operate:

1. Open the war3x.mpq file (not war3.mpq) in the World of Warcraft folder with WinMPQ, and find the file ui \ glues \ mainmenu \ mainmenu3d _ exp \ mainmenu3d _ exp.mdx in it. This is the default background when we entered war3. We just need to replace it.

2. how to replace it? For example, if you change the default background to a UD picture (I think this picture is cool), you need to find the file UI \ Glues \ Singleplayer \ Undead 3D _ exp \ Undead3D_Exp.mdx, and then copy this file with Extract, and change the file name of Undead 3D_Exp.mdx to MainMenu3d_exp.mdx

3. Finally, click "Add" in the WinMPQ editor to import the file you modified, and a dialog box will pop up. Enter ui \ glues \ mainmenu \ mainmen3d _ exp \ and click ok.