ps3 fat stuck in demo mode

This ps3 fat has been in demo mode for the longest I can remember and I still have no idea how to get rid of it completely, I dont get what it is or how it even got there but I need help getting rid of it for good, Ive seen people using computers/laptops or whatever to get rid of it but i have neither of those. Is there a way to get rid of it completely without the hassle of getting a computer or something.