How do you get rid of the "Personal Use" phrase on some of the Caps in the Billy Argel Font?

Buy a commercial license. All of Billy Argel's fonts on DaFont are trial/ demo versions, meaning that:

There are restrictions on how you can use them, (most likely, printing and embedding are not allowed; you could use them in an app like Microsoft Word to see the text display, but you might not be able to create a .pdf document, for example).

I think Billy has given up font making, and returned to doing skateboard designs. koeiekat may be able to provide you with contact information. As far as I know, he's no longer answering correspondence at the contact info/ site info displayed in his DaFont profile or in the 'Note of the Author' section on the details pages.

It so seems that Billy Argel never replies to email or his pages at http://billyargel.blogspot.com.es/search/label/Fonts and http://www.fontspace.com/billy-argel. Also see http://www.fontspace.com/profile/Billy+Argel

As he never responds the only way to get rid of the phrases is to remove them with a font editor. No numbers, no punctuation though. Keep in mind, if you do so keep the use to strictly private and never ever show that use anywhere on the Internet.