Open Outlook
Click File
Click Options
Click Mail
Under Compose messages, click Signatures
Select the email account from the Choose default signature for: dropdown (if applicable)
Select the signature to edit from Select signature to edit:
Edit the signature text in the Edit signature box
To change signature formatting, use the formatting toolbar in the editor
To set when the signature appears, use the dropdowns:
New messages
Replies/forwards
Click Save
Click OK