Open the Manifest.json file. I am using the free Visual Studio Code from Microsoft but you may use other applications available to you. The .json file should look as shown here:

Change the following values to be valid for Ubuntu server:

• Value name changes to UbuntuServer16-04
• Value publisher changes to Canonical, please be aware that no spaces should be used in the name
• Value displayName changes to Ubuntu Server 16-04, this name will be visible to the customer in Marketplace
• Value publisherDisplayName changes to Canonical, this publisher name will be visible to the customer in Marketplace
• Value publisherLegalName changes to Canonical, this should be the legal name of the vendor/publisher

The other values do not have to change. To better understand the Manifest.json some further explanations of some values. The value path defines the paths to UIDefinition, DefaultTemplate and CreateUIDefinition JSON files. It should not be changed. As shown in the previous screenshot, the value for categories defines where your image is visible in the Marketplace. You may define several categories here.