To update your profile, refer to this tutorial.
During the update of your profile, if you have missed a mandatory field when updating your profile an error message will appear:
The page will advise the field that requires further information
In the example the Last Name field (via the Personal Details tab) requires a first name and a surname.
NOTE: You will not be able to continue without updating or filling in all mandatory fields (indicated by a *) next to the field header
1) To fix this error, complete the mandatory field as required, where it is required
2) Click Update Profile to apply changes to the profile
3) A green banner will appear on the page, confirming you have updated your profile successfully.