Upload theme
In order to be able to upload themes, the only thing you need to do, is to create a user. This is to prevent spammers and duplicate uploads, and if a user is caught misusing the service, the IP will be banned and the user will be deleted along with it's theme uploads.
With this new uploading system you will automatically be marked as the themes owner, and will be able to update the theme from this page.
When your user is created, go to the "Upload theme"-page - you dont have to do anything in the site's backend.