In order to make changes to multiple customers at once or to quickly start over somewhere else, you have the option to export all your customers through an XLSX file.
First, click the Import / Export button on your Customers overview and then click the Generate XLSX file button on the overlay. Open the file in Excel.
You will find an overview of all your customers and their information listed in the file, enabling you to make quick, bulk changes to some or all customers. After you've made the desired changes, re-upload the updated file to the Editor using the import feature.