Important notes before you begin:

1. Every time you click generate it uses a credit, even if you cancel the end results.
2. Every time you hit generate, it uses one of your 50 latest generation spots to store the 4 choices it offered. Make sure you have saved any images before you start so they don't roll off without you noticing.
3. This is still in beta, and there is a notice that this does not save your image. You must hit download to save the final file to your computer, or you will need to manually piece together the final image at the end.
4. DALL-E does not see the whole painting, only what is in the generation square. Make sure to have sufficient overlap, and describe what you want to see in the square. Anything extra in the description may cause unexpected and unwanted results.

Find an image you wish to out paint. Click it to open it.

In this case, you'll see the original prompt you used, along with the 1024 x 1024 image.

Click the ellipse button, and select Edit.

On the top right you have the download button. Use this to save the final result to your local storage.

The bottom center holds the cursor, the hand that allows you to move the image on the screen, the eraser, the generation panel placement tool, and the upload image button.

The right side has a slide that controls the size of the eraser brush.

the bottom right allows you to zoom in and out.

Now that your image is uploaded, let's get started. Let's go up first to expand the top of the painting. Note that your prompt carried in. Make sure you have sufficient overlap so DALL-E has enough context to continue the painting. Position the box and choose Generate.

By using the left and right arrow buttons you can cycle through the 4 choices. This looks like a good match, so I'll hit Accept.