Once you’re done building your theme, you can export it. When you do, it’s saved as a zip file. If you’ve been working in an external editor, you’ll need to zip up your theme. Make sure it follows the Weebly directory structure!
Your theme is named based on the name of your zip file, so you’ll likely want to change the name of the zip.
Deliver your zip file to any Weebly user and they can import it and use it in their site!