Im downgrading a PSP for my sister, its a Slim, and its on 3.71. She wants to put 3.71 M33 on it, I know how to do this with fat PSPs but ive never done it on a slim, is it possible? Would I have to downgrade it to 1.50 first then up to 3.71 M33? Plus, are the updates to 3.71 M33 the same as the updates for the Fat PSP or do I need some special ones for the slim? Thanks.