There are a few ways to unsubscribe. The fastest is to log in and go to "My Profile" at the top. Under emails it lets you choose which (if any) emails you wish to get.
Another way is to reply to an email with a polite note asking to unsubscribe. There's an email exchange to make sure that you are really you. Just follow the instructions and the Bot will do the rest. It's a lot slower than doing it yourself.
You can also turn on 'one-click unsubscribe' in your email settings so you can use the one-click unsubscribe link on your emails.