How to change customer's default payment source

Using Dashboard

1. Go to Customers;
2. Find and click on the customer in question;
3. Scroll to the section 'Payment Sources';
4. Find the Payment Source you would like to make a default one;
5. Click 'Actions' > 'Make default'.

Success!

Using API

1. Generate a new payment source for your targeted Customer
2. A simple API POST to /v1/customer/{id} by setting the default_source using the "_id"  value  found under payment_sources for that customer

   {
        "default_source":"1234567890"
    }
   	

Success! The default_source "value" for that customer has now been changed.