need help with factory reset

[thebackdraft]

I have a Galaxy Note 3 with a broken lcd that I need to do factory reset on. It's been replaced by insurance but I don't want to send it back until I erase all my old data. Any ideas on howi can do this. The Samsung people in Best Buy have tried to reflash it but when I try to sync it with Kies it still tells me to unlock the device, which would suggest that it hasn't been reset sincei keep it locked. Thanks for any help.