In the dvd is a red key light and say safe how i can take it out

Do you have a key ??? try your combination and A or B
Open with key insert new batteries and reset combination.

Download the user manual to your set from net. It will have all details.

if when you push LOCK button on remote red key and lock display should disappear?

I need an instruction Manual for a Nutool sf20 safe

To open a Safe International Digital Electronic Safe

User override key to open safe

Then:

a. Inside the open door you would find hidden a red button press this button, the yellow light will be on, input the user code in 30 seconds try 1,5,9 then press A or B to finish

b. If the yellow light keeps flashing with beeps the code is wrong( revere to user manual)

c. To change code repeat step a.

Test your new code before closing safe.

When the red light blinks that means you are entering the wrong code. If your batteries went dead the safe delets the user code Check your owners manual for the default factory code number. Programing instructions.

The operating instructions on the ES20 as per the crappy manual:

Open safe using emergency key provided

Insert batteries in the box inside the door

Opening the safe
a. pre-set factory code 159
b. input 159 (the yellow light will flash and the buzzer will beep), then press B or A button, the green light will be on, rotate the knob clockwise, pull outwards, the door is opened

Closing the safe: close the door, input the code (the green light will flash for 5 secs). Turn the knob anti clockwise, the control system will activate and the safe will be locked

Changing the code: open the safe, press the red button located inside the door, the yellow light will go on indicating the code can be changed. Input the new code (1-8 digits), then press A or B button, it shall be confirmed by two beeps indicating the new code has been accepted and stored. If the yellow light and buzzer beeps 3 times the code is invalid - try again

Emergency Key - store in secure place NOT inside the safe. Remove the override cover in the centre of the face of Safe (its a silver plastic panel with Sandleford Electronic Safe ES20 on it), insert override key (a cyclinder key) - hidden underneath the override cover panel - and turn anti clockwise, rotate the knob clockwise to open door

Changing the Battery - If the red and green light are on this indicates that the batteries are low and require changing. To ensure the batteries have been installed correctly test before closing the door

References:
1. Operating instructions EA Electronic Safe
2. http://www.secustar.com/products-en/estype-safe.htm

I have pin code but batteries went flat while I was on holiday, how do I unlock my Hardline digital safe? I do not have override key

It's Not The dvd drive key otherwise you'd get the three red light lights. It's most probably a bad firmware flash try and reflash it to the original firmware with the same dvd drive key and see if that works.
Alex