In the Profile section you can change your profile details except your Login ID.
Go to Settings > Profile to see and edit the following fields:
Login ID: Not editable.
Contact Name: Your name.
Address 1: First line of your postal address.
Address 2: Second line of your postal address.
Fax: Number of your fax machine (if applicable).
State or County: State or county of your postal address.
City: City of your postal address.
Country: Country of your postal address.
Postcode/ZIP: Post or ZIP code of your postal address.
Phone 1: Preferred contact phone number.
Phone 2: Secondary contact number.
Primary email: Your main email address.
Profile language: Preferred language.
Alternate email: Your secondary email address.
Assist in autofilling recipients (enabled by default): Select Assist in autofilling recipients to populate the To and CC fields with contacts in your address book while composing an email.
Signature when composing new email: Your name and email that will be displayed when composing and sending an email.
Signature when replying or forwarding: Your name and email that will be displayed when forwarding an email.
Design: Select Design to modify the appearance of signature, for example, by changing the font or alignment of your signature.
HTML: Select HTML to view the html code.
Preview: When you're finished editing your signature, select Preview to see how it will appear in email format for your recipient.
Select Update.