What skills are involved/necessary to modify hardware such as the ps3?
So I've been a casual gamer on and off for years as real life obligations permit, but I followed with interest the Original Xbox mod scene, and have been playing catchup with the PS3 jail breaking scene. After some of the articles I have read, I find myself interested in the general methods one would use to achieve a successful modification to hardware in order to make it do what you want, especially when that hardware has been secured using some method of protection. This doesn't have to be ps3 specific, it could be any piece of hardware that is more like a computer. I admit that it may be way over my head, but I would really be interested in any links or resources someone could provide, along with any of the required tools, in order to begin to learn something like that. I do not even know where to start. Hopefully this doesn't sound too stupid, I just am really curious and would be interested to learn as a possible hobby/challenge. Thank you in advance for your time.
Edit: Clarified what I meant.