PS3 Update to System Software 4.89: Here's a Full Guide for You
Update PS3 Via USB To 4.88 4.87 or 4.86 ( Using Update via Storage Media ) - YouTube
PlayStation 3: Sony releases Firmware 4.86 for their 13 year old console - HFW 4.86 released, SEN Enabler updated & PS3HEN to be updated soon due to no kernel changes! - Wololo.net
PlayStation 3 Firmware Update 4.40 – Download Here
PS3 Update to System Software 4.89: Here's a Full Guide for You