If you are in a group practice, you only need to make the change on your Personal profile page:
Click Personal > Profile.
Click Edit at the top-right of the page.
Change your details as desired and click Save Profile.
If you are in a sole practice, you also need to update your Group Name on your Settings page (you do not need to do this if you are in a group practice):
Click Settings > General.
In the General Settings section, click Edit on the right.
Change your Group Name and click Save.