Where is text on Galaxy S5 and how do I delete

[AC Question]

Text files are at maximum. I wish to delete them.

 

[ManiacJoe]

Using a file browser app, navigate to the folder containing your text files, select some for deletion, delete them.
Some file browser apps have there own "recycle bin", which you may need to "empty" to get the space back.

Are we really talking about text files (or any other files), or are you referring to text messages (which are not files)?