This article is related to PromoteMyPlace Version 2 only. Not sure which version of the application you're using? See Which version of PromoteMyPlace am I using?
From the ‘Website’ dashboard, choose ‘Template - Header Image’
Select ‘Add Header Image’
Select an image or upload a new image (see article on how to upload a new image)
Pop up box appears where you can add options, see the article ‘Add text and button to header image’
Once you’re ready to put your changes on the live site you will need to publish the website changes using the orange 'Publish Changes' button at the top of the screen