Navigate to the NC Intensity website (havcvolleyball.org). Click on the “Login” button in the upper right hand part of the page.
Log in using your NC Intensity Username and Password. (If you've forgotton those, click on the "Forgot Username and/or Password" link to reset them.)
Once you log in, you should be taken to your Account Management page. The first section of that page is titled Payment Information. Toward the right part of that section will be a green box labeled "Make Payment". Click on that link and you'll be presented with options for making your online payment.