Step 1: Download the proper CFW for you from the links above and plug a USB thumb drive into your PC
Step 2: on the USB drive create a folder directory called PS3/UPDATE and place the REBUG Update into this folder and rename it PS3UPDATE.PUP
Step 3: Plug your USB into your PS3 and scroll to system update and select update via storage media. It will scan your USB and then select the Update. Allow that to finish and your done.