Visit a customer's profile by searching for them or by by selecting a customer from a an available segment.
Under the customer's name, you will see the currently assigned users. If you are not assigned to the customer, you will see an Assign to Me button. Click the button to assign yourself to the customer.
Select Yes I'm Sure went prompted.
Once you've been assigned to the customer, your name will appear on the assigned list and the Assign to Me button will will no longer be displayed.