removing accounts from notification centre

I am returning my Macbook Pro (OS X Mavericks) to the company. Since I have to make sure the files and other apps are intact, I only deleted my internet accounts from the System Preferences. I've also deleted the saved passwords from the Safari Preferences. However, the notifications center still shows notifications from my Facebook account (comments and messages). How do I remove my accounts on the notifications center? The best I can do right now is to turn off notifications from the preferences, but if the new user turns it back on he will see notifications from my FB account. Please HELP!