Go into the directory. Click on "My Household" on the left. In the top right, click "Edit". Assuming you are the Head of Household or Spouse, I believe you can edit anyone's phone number. If you are the child, even an adult child - I'm not so sure. In that case, work with your membership clerk to have it changed.
Have you searched the
Help Center? Try doing a Google search and adding "site:churchofjesuschrist.org/help" to the search criteria.
So we can better help you, please edit your
Profile to include your general location.