How to upload an updated extension file to the Extension Warehouse

I want to update an extension I have published in the Extension Warehouse.

When I log in to my account in, goes to My Extension and select edit the extension - I’m able to edit all the the published information and Publish the changes.

BUT - I’m not able to add the updated rbz file. There is no file upload dialog available on the page.

Strangely I can select the Upload an Extension icon and start publishing/uploading a new extension.

How can I upload an updated rbz file to an existing published extension in the Extension Warehouse?

Don’t select Edit Extension on the snowman menu. Instead choose Create New Draft.