HELP! Signing in to PSN without updating to 4.85

Hi guys i have a PS3 (HFW i think) with the firmware version of 4.84, it has HEN 3.0.0 (updated itself today) and mmCM but not fully jailbroken, I heard that updating to 4.85 is a risky thing and actually i don't know how to do it but i just want to play online again but whenever i try to sign in it says a new update is out and then i press x for it to automatically update but it says "Until further notice please stay on this firmware" so I cannot play online, So here's the question. How...

HELP! Signing in to PSN without updating to 4.85