I would recommend installing Rebug 4.30.2 rather than Rogero 4.40 v1.03, here's a guide to install Rebug 4.30.2 on top of 3.55 CFW/OFW:
1- Make NOR/NAND dump (optional) if on CFW:
Install latest version of multiMAN (4.30.00), plug in a FAT32 formatted USB flash drive into the right USB port, launch multiMAN under Games and go to mmOS > Press [O] on any file > Open in HEX viewer > Press [SELECT] > Press [START] > Export GameOS LV2: Select No > Export HV LV1: Select No > Export FLASH: Select Yes
2- Install Rebug 4.30.2 from XMB:
Download Rebug 4.30.2 from Rebug's website, verify the md5 hash, rename the PUP to PS3UPDAT.PUP, put it on your FAT32 formatted flash drive in PS3\UPDATE, go to System Update and Update via Storage Media. Make sure there's NO original game disk in the drive and that you DON'T Update via Internet or else you would risk installing OFW higher than 3.55!
3- Install Rebug Update Package 0.1:
Download Rebug_Update_Package_0.1_4.30.x.pkg from Rebug's website, verify the md5 hash, install it from Package Manager, launch it under Games and follow the on screen prompts, the screen will freeze for a while when you press Yes, do NOT force shut down your PS3 at this stage or else you will get a nice and shiny RSOD! Just be patient and wait for it to finish what it's doing, it will reboot if needed when finished. Once the PS3 has rebooted, you can delete Rebug Update Package from your XMB as it is not needed anymore.
4- Enable QA and spoof to 4.40:
Install Rebug Toolbox from Package Manager, launch it under Games, go to Utilities and enable QA. This is to ensure easier and safer downgrading. Now go to Selector and change System Mode to Rebug, this will spoof to 4.40 to prevent accidental updates and allow PSN access. You can also change XMB Operation Mode to Retail and Debug Menu Type to CEX QA to ensure you have the Retail menus instead of the Debug menus which you probably won't need.
Does multiman work on rebug?
Also if a lower version of multiman is installed on both rebug or rogero, and I want to update, do I have to uninstall multiman and then install the new one or do I simply install the new one without any uninstallation. Will the new multiman overwrite the old one?
Of course it does, everything works on Rebug 4.30.2!
When you install a newer version of mM on top of an old version, it will replace the older version.
what are the differences between rebug and rogero. why is rebug better?
Rebug is simply the most solid CFW out there. It's a complete CFW and is reliable and stable from release. Rogero CFW is OK once it becomes stable, but he has to release many versions before it becomes stable. For example, he had to release around 10 versions of his 4.30 CFW before it became stable and now he's on v1.03 of his 4.40 CFW and it's still lacking some features such as disabling Cinavia. You wouldn't want to keep upgrading your CFW whenever a new version is released.
Moreover, it is much easier to downgrade Rebug CFW if you ever need to. You just enable QA and install Rebug 3.55.4. Downgrading Rogero CFW on the other hand is more complicated because you have to use a downgrader PUP and dehash which is more risky.
you seem very knowlegeable. I have a question. Lets say I am running CFW 3.55 kmeaw. Now I want to update to Rebug. DOes the USB with the update have to be in FAT or NTFS. Because I know the latest version of Multiman supports getting games from an NTFS USB. But does Rebug also support NTFS? Also before installing Rebug can I put the rebug update on a ntfs usb and then update or do I need FAT?
The PS3 can only read FAT32 USB drives. Only mM can read NTFS drives on the PS3 (on any CFW) but with limited functionality, basically just to transfer data from the external drive to the internal drive and that's it.
To answer your question, no you cannot install CFW/OFW from an NTFS formatted drive.
Now I have one last very important question on installing rebug. I live in Bangladesh, a poor third world country. We have had huge electricity problems. The power may go out at any time. The tutorial says that "do NOT force shut down your PS3 at this stage or else you will get a nice and shiny RSOD". If I am installing rebug and the power goes away what will happen?
can i pm you?
You would brick your PS3, that's why the 1st step in my tutorial which says (optional) would be very important in your case. Having a valid dump would be your only chance in recovering if the power goes out while upgrading your CFW/OFW (any CFW/OFW, not only Rebug). You would still need a hardware flasher for a chance to recover.
So if you have power outages in your country, I would recommend connecting your PS3 to a UPS when upgrading it. Or at least if the outages are on a regular schedule, make sure you perform the upgrade during a time when you know there will be power for at least 1 hour in advance.