How to remove password?

I am having "Samsung Galaxy Note II".I tried to set up VPN on my device.Then it ask me to set-up a pin so,i have to forcefully set-up pin also.but now I am not able to remove it.even i have disable all the administrators.Clear credentials option is greyed(disable).

when i went to change Screen Lock type there all the option except password was disabled.I don't want to reset my device to resolve it.so please give me another solution please.