Step 1: Download the file below and plugin a USB Stick with at least 500MB on it.
Step 2: On the Root of the USB make a folder called PS3, Inside that folder make another Called UPDATE. This is where the update will go.
Step 3: Copy the CFW_PS3ITA_441DEX_REV4.PUP to the UPDATE folder on the USB and rename the files as UPDAT.PUP Some windows won't show the PUP so if it doesnt just rename it PS3UPDAT
Step 4: Plug the USB into your PS3 Running OFW 3.55 or and DEX Base CFW and go to System Update, Select Via Storage Media and install and allow the system to boot on its own.
This firmware also Comes with a Backup Manager PS3ita Manager V1.30
DEX CFW: http://www.mediafire.com/download/xzb...
PS3ita V1.30: http://www.mediafire.com/download/5ir...