You'd have to downgrade it to 3.55 first, you'll need an E3 Flasher or another chip to downgrade the system - then you can go right back to 4.40. E3 Flasher is recommended since you can dual boot OFW and CFW with it, playing online on CFW is not recommended as you may end up getting your system flagged or banned altogether.
Do you know with eflasher do you have to take your ps3 apart or do you plug it in