Take off the oval shaped cap and access the override lock,
You will see the serial number on a label for the lock,use this number to obtain a new set of keys.
There's contact details for Replacements in manual, or take the safe along to a locksmiths if it's mobile.
There's several ways to get into a double bolt but you don't need to know that if the label is there. :)
e manno
November 2012