You can easily upload your own custom header to your webstore, just follow these steps:
1. Login to your account.
2. Go to your “header” tab.
3. Under your "Header" tab choose the "Upload header" tab.
4. Click on “Choose file” and choose your header from your computer.
5.Once your image loads in your control panel it will automatically be added to your Webstore.
If you have any other questions relating to changing webstore’s header feel free to comment below.