These instructions are based upon my location being within the United States and my language being English; however, I'm hopeful that the instructions transfer easily to My Nokia web sites for other locations and languages.

Starting out:

1. Go to Nokia.com
2. Follow through to the Nokia website for your region as necessary.
3. Tap the "My Nokia" tab near the top right of the page.
4. Log in to My Nokia if necessary.

To enable or disable email or SMS updates:

1. Tap the "Edit my details" link.
2. Check or uncheck "By e-mail" and "By mobile messaging" according to your preferences. The site will allow you to uncheck both options.
3. Tap the "Submit" button near the bottom of the page.

To close your My Nokia account:

1. Tap the "Edit my account" link.
2. Tap the "Remove backup data or cancel your My Nokia account" link.
3. Select a reason for unsubscribing. "Not satisfied with My Nokia" appears to be a good choice, though "Not satisfied with Nokia" or "Deceased" might also be tempting options.
4. Tap the "Unsubscribe" button.