Go to Settings > Privacy > Factory data reset.
It will erase all your settings and apps and whatnot. Also, if your contacts aren't synced to Google, they will be deleted also. So go to google.com/contacts and make sure they are there before you do it.
It will erase all your settings and apps and whatnot. Also, if your contacts aren't synced to Google, they will be deleted also. So go to google.com/contacts and make sure they are there before you do it.