Exporting a customer list takes a few steps. To begin, you'll want to navigate to your list of customers which can be found under Customers>Manage Customers, as shown below.
From here, navigate to the button that is labeled "More Options". Clicking on this will bring up a menu with other options for you to chose from. The first two options on the list are Export CSV and Export PDF. Chose the file format that you would like your customer list to appear as and click on that option.
You will get a notice that it is now generating your file in the background. To download this file, navigate to System>Alert Module as shown below.
From here, you'll want to click on the "Customer" tab. At the top of the list, you'll see an entry that has a reference of "CustomerCSV". Click the eye icon on this record to expand it and you will find a download link for your file. This will download your exported customer file and you should be all set!