From the Helpdesk dashboard you can click on any outstanding invoices or hover over Billing in the top navigation bar and click on Invoices of Recurring charges.
If you clicked on the Invoices button from the navigation bar, click on the invoice that has a status of not paid.
You are given the options to use credit card or PayPal. If you choose a credit card, fill out the appropriate fields. If you choose Paypal, you'll be taken off-site to complete your transaction.
Once you're done, you'll receive a receipt by email.
