Although professional locksmiths rarely take this course of action it s possible to cut a locked safe open.
Cutting open a floor safe.
When an untrained or inexperienced person tries to open an old safe through drilling method the attempt gets wasted.
Drilling a safe is the most common and practical method of opening safes because it creates only few simple repairs and it also works effectively.
Drilling is a common practical commercial method of opening safes because simple repairs can be made to restore the container and lock to their original conditions or better allowing the safe to be put back into service whereas cutting or prying would completely destroy the safe.
Depending on the material used to construct the safe several sets of saw blades may be needed as they are dulled down.
This process is messy noisy slow and destroys the safe.
Use an angle grinder and cutting wheel to cut the back or bottom off the safe.
Another concept for how to open an old safe is scoping.