Doesn't do anything with border gore. Only destroys large realms like Blobassids or Blobling Francia.
To install you need to unzip the file into your mods folder and then move the .mod file into the mods folder.
To use it you'll need to right click the title shield of the person you wish to de-blob/destroy. It works only on Dukes, Kings or Emperors but does not allow to do it to the pope.
AFAIK it requires nothing.