The main home page of the MemberGate site is also considered the Public Portal.
The main image of the public portal can be edited under Content Portals Edit Public Portal
Under the Images section click on the Upload Main Imageoption in the Graphic to Appear at the Top of the Page field. Select the image from your local drive. The image can be a png, jpg or gif.
Editing the image for the Members Homepage, or the Members Portal Page can be completed under under Content Portals Edit Member Portal and follow the same instructions.