We would be very sad to see you go. It does not happen very often as we keep most of our customer very happy. If you decide to leave us, please let us know why. Send us a quick note, we would really appreciate your feedback. If there were a couple things that did not work for you - we would love to hear about that and help you fix it. Your feedback will helps us build better product for our existing and new customers so please tell us why you are about to make this decision and we will make sure we try to improve. Thank you for your effort and consideration.
Go to Left Menu, select PROFILE > Account Details and click "You can delete account here" link at the bottom. Here is a quick video that shows the whole process: