Downgrading a PS3

So my brother has an old PS3 and currenly got 4.25 on it, and wants to downgrade it to 3.55. He did have way under 3.55 when he bought the console. Is some hardware flasher the only way to do it or is there a software way?

thanks

only the hardware thats of course if your PS3 is downgradable .

ok, so you're confirming that if it is downgradable a hardware flasher gadget thing is the only way to do it?

yea if its downgradeble the only way so far is a hardware.

thanks, that was unfortunate :/ It's an old phat from prehestoric times so i hoped it was doable via software :/

well since its fat then its downgradeable but only via Hardware but there are alot of News about new CFW 4.20 and also 4.25 blue Disk cracked but unfortunate you should be already on CFW 3.55