Navigate to the Account Settings page by clicking on your name in the top right hand corner of your portal

Select the 'Users' tab on the Accounts, Users & Entities table

Identify the user that you would like to re-send an invite to

On the far right, under the 'Actions' column, click the Mail Icon to send any user a new welcome email/portal invite

Select the Email Subject, Email Header, and Organization name in the pop-up

Send the invitation!