ow do you delete parts from the tubing and piping database

The routing add-in comes with the standard piping and tubing database and a design library that has some piping components.  I have created my own tubing and piping library and would like to cleanup the "Standard tubing and piping database" by deleting the components that I do not need.  Starting with an empty database would be great.

I don't see anyway of manually  deleting parts from the library.  I don't want to just hide them