Description copied and modified from original mod ( https://www.nexusmods.com/skyrimspecialedition/mods/33574 ):


Introduction:

This mod replaces the main menu (and in theory everything else you want) every time you start Fallout 4.

Requirements:

• F4SE
  

Installation:

Easy:

• Install like any other mod using the Mod manager of your choice.
• Install one of the replacers avaiable that are explicitly stated to be compatiblee with this
  
  

Custom:

• Install like any other mod using the Mod manager of your choice.
• Create a Folder in your "Fallout 4\Data" Directory called
  "mainmenuwallpapers" (can be changed using the configfile)
• Place a new Data directory for each replacer in a seperate child
  directory (The whole path for a meshes directory should be "Fallout 4\Data\mainmenuwallpapers\[your replacer name
  here]\Data\Video" )
  
  

WARNING: This mod can and will replace data in your data directory by default. Use at your own risk.

You should not need to change any configs if you use a compatible main menu replacer, this mod uses defaults that work with these replacers.

By Default this mot picks one random directory inside the "Fallout 4\Data\mainmenureplacers" Directory.
Then it copies EVERYTHING inside that directories "Data" child directory OVER your "Fallout 4\Data" Directory.
Yes everything. In theory you could place plugin files in there but please don't.

Thanks to cupcakeninja6 for an example:


You can change this behavioud in multiple ways using the included config file:

[[Source]]
The Configfile can contain multiple Source blocks.
Each source block defines one source directory.

Directory
This Property selects the directories the mod looks for replacers. 
You can use absolute directores or paths relative to you "Fallout 4" directory
Use this for example if you want to move the replacers away from your data directory.

Multiple Directories need to be separated with a | character.

Examples:

C:\Replacers
.\Data\[my cool other replacer dir]
.\Data\[music replacers dir]|.\Data\[meshes replacer dir]

Multiple source Directories Example:

Folder Structure:

• music_replacers
  • replacer1
    • data
      • music
        • [files]
          
        
        
      
      
  • replacer1
    • data
      • music
        • [files]
          
        
        
      
      
    
    
• menu_replacers
  • replacer1
    • data
      • video
        • [files]
          
        
        
      
      
  • replacer2
    • data
      • video
        • [files]
          
        
        
      
      
    
    
  
  

Config File:

[[Source]]
Directoy = '.\Data\music_replacers'

[[Source]]
Directory= '.\Data\menu_replacers'

In this case the mod would pick one replacer from the music_replacers
directory and one from the menu_replacers directory and merge those two
together that way even when he picks the same menu replacer you could
always get differrent music

Destination
This property chooses where the copied files get put.
Once again relative (to "Fallout 4" directory) and absolute paths are supported.
Use this for example if you want the mod to write in a seperate
ModOrganizer mod or in the ModOrganizer overwrite directory so it
doesn't automatically overwrite other ModOrganizer Mods.

Filter:
This Property chooses which files get copied.
This is a regular expression (see: https://en.wikipedia.org/wiki/Regular_expression )
It checks the relative path (relative to the "[replacer]\Data" Directory)
so it needs to check for example ".\Data\Video\MainMenuLoop.bk2"
The check works case insensitive so upper lower case will be ignored.
Example: "^Meshes\\.*" would select everything inside the meshes directory but nothing else.

You can also overwrite the filter for specific source directories by adding them to the corresponding Source block:

LogLevel:
This Property sets how many messages get logged. Possible Values are "Error", "Warn", "Info", "Debug" and "Trace"
"Info" is recommended


Reporting Problems
If you have any problems please set the Debug.LogLevel Config to 5 and send me the Config file and the logfile.
That way I can look into what's the problem.

Logfile Location:
Data/F4SE/Plugins/MainMenuRandomizer.log

Credits & Special Thanks
hellstorm102 & LLFBandit for the Legendary edition Randomizer and Randomizer Plugin.
meh321 for the .NET Scripting Framework.
cupcakeninja64 for the Example.

Bethesda and NexusMods for Skyrim and this site respectively.

pixel-perfect for the shuffle icon.
lanastara for Main Menu Randomizer SE
Sweet6Shooter for the shuffle icon.


Source code can be found here https://gitlab.com/monyarm/main-menu-randomizer