Select the main "Portfolio" link in your Account Management menu.
Then select the portfolio that contains the desired homepage image, and click "Add/Edit Images", which will open up your image list for that portfolio.
Locate the desired homepage image and select "Edit Image".
Select the box next to "Set this image as the main image for the homepage of my site. Checking this box will replace the current image as your homepage image"
Click "Save". Your new homepage image will be set immediately.
If you are using a slideshow option:
You must add images to your slideshow in order for them to appear on your site. To begin, select the portfolio that contains the image you wish to add, by clicking on the portfolio title under "Portfolio Management".
Next to each image in the portfolio, you will find a button labeled "Add to Slideshow". Clicking this will instantly add the image to your slideshow.
To remove an image from a Slideshow, simply click the "Remove from Slideshow" button, which will appear if the image exists in the slideshow.