Here is a Simple way to destroy every title there is.

[FunGaming]

For those that want to destroy any title in the game, make a folder called run in your Crusader Kings III folder in documents. In there create simple text files like for example I placed in there destroy_britannia.txt now in that txt file add one simple instruction ->>> Destroy_Title e_britannia

save the file
in game open de console and type run destroy_britannia.txt and foila empire destroyed. You can do this for every title there is.

 

[FunGaming]

Update with info how to do it