Changing the persons

Hi together,
just installed a local instance of the GNUmed package successfull (found
ist a little bit tricky ...) There are a few 'fake' persons still included,
e.g. Cilla Raby as a patient and so on.
Wondering, how to 'deactivate' them - but especially I do not figure out
how to change Dr. L. McCoy to another name to be the 'leading' doctor or
owner of the branch who is shown in the screens.
The documentation seems to be lacking this information.
Can you give a short explantation? Thank you.
W. Zimmermann from Darmstadt, Germany