This is a disclaimer : DO NOT use Techniques described in this video for nefarious purposes or illegal actions. This videos in is intended to bring awareness to the subject . Do not use these boxes for anything important, especially the older ones as they are historically incredibly easy to get into and frankly insecure. I am not the first I like this subject and multiple other videos are on YouTube describing this issue, and please bear this in mind before commenting or complaining. In this video, I demonstrate fundamental how to and say how weak they are without a code and why are you should not use them if at all possible . 
The company and other like them has addressed some of these faults in your models, so please check what one you have .