To go along with the recent PSN access enabled by Rebug, PSX-SCENE member TOGxFTW has put together a video guide, and a written tutorial, to help other members get their 3.55 machines running PSN once again using Rebug's Update Package 0.7. If you do not use Rebug CFW, then you can instead apply the 4.11 Version Spoofer 2.2 to your current CFW (certain restrictions apply: No Cobra. No TB v2.6+).
Step 1 - To insure you don't get YLOD, make sure you are on 3.55 OFW; download 3.55 OFW here - PS3UPDAT.PUP
Step 2 - Download CFW http://rebug.me/rebug-3-41-2-rebug-3-55-1/ and CFW Updatehttp://rebug.me/rebug-update-package-0-7-3-55-2/
Step 3 - Drag and drop the .PKG File and in the root of your Flash Drive
Step 4 - rename the REBUG_3.55.2_PS3UPDAT.PUP in the .RAR file to PS3UPDAT.PUP
Step 5 - Make A folder called PS3, in the PS3 Folder, make another called Update and drop the .PUP file in there.
Step 6 - Drag and drop the PS3 Folder into the root of your Flash Drive
Step 7 - Safely eject your USB Drive and Plug it into your PS3
Step 8 - Update your PS3 to Rebug CFW 3.55.2 by navigating to Setting/Update/Updating via Storage on your PS3, click X when it says install
Step 9 - Once Install finishes, navigate to Game/Package Manager/Install Package Files/Standard Package Location on the XMB and Install the .PKG
Step 10 - Open up the Rebug Update Package 0.7 under game and Press Enter (X) when prompted
Step 11 - Your PS3 will appear frozen for about 5 seconds. Press (O) when prompted to exit the program.
Step 12 - Navigate to Package Manager/Install Package Files/PS3 Hard Disk and install Rebug Selector 1.6 .PKG
Step 13 - Open up the CexDex Program under game, when it displays GUI, on your controller press L1 + O to go into Rebug mode, confirm this by looking and the setting at top of GUI
Step 14 - Exit the program via PS Button and Sign In!
NOTE: if you get an error signing in, setup your network settings again and try signing back in ^_^