This is a tutorial from start to finish on how to convert a CEX console to a DEX console. If you don't know what you're doing or need someone to explain what DEX is to you, you should probably leave now. Also, be warned - if you mess up anything in this tutorial, you risk bricking your console. Follow the instructions right and you should be fine.
Note: This conversion does not require the installation of Linux or any hardware modifications, but it is recommended you have an E3 flasher or similar device in case you do end up bricking your console.
You're going to need:
-3.55 PS3 (preferably running Kmeaw's custom firmware)
-USB Device with around 1 gigabyte of free space
-jaicrab's preloader (Download)
-FactoryServiceMode Tool (Download)
-CEX2DEX Tool (Download)
Once you have all of the above, you're ready to get started
1. Install the FactoryServiceMode pkg on your PS3 and use it to boot your PS3 into Factory Service Mode. When done, confirm your console is in service mode by turning it on and seeing if the red box is there in the lower right hand corner. Power down your PS3.
2. Take all the files from Preloader.zip and extract them onto the root of your USB stick. Rename "Lv2diag.self.flash" to "Lv2diag.self".
3. Eject your USB from your PC and place it in the rightmost USB port of your PS3 (your PS3 needs to be turned off). Once it is securely in place, turn on the console. Nothing is going to come up on the screen, and eventually the PS3 power LED will start blinking. DO NOT TURN OFF THE CONSOLE, it is dumping your NAND/NOR. Wait for it to power down itself.
4. Once your console turns itself off, remove the USB from your PS3 and plug it back into your PC. There will now be a file on it named "Backuprflash.bin" (Note: You may have to enable displaying of system files in order for it to be shown). This is your dump of your NOR/NAND - if your console is NOR, the filesize should be 16mb. If your console is NAND, it will be 256mb.
5. On your USB, rename "Lv2diag.self" back to "Lv2diag.self.flash" and then rename "Lv2diag.self.exit" to "Lv2diag.self". Place the USB in the rightmost USB port of your PS3 (turned off), then turn it on. It should turn itself off after a few seconds. When it turns off, remove your USB and boot the PS3. It should now be out of factory service mode.
6. Install the eEID_RKDumper on your PS3. Run it, and it should cause your console to blackscreen. It will reboot after a few seconds, just give it it's time and don't interrupt it (it is dumping your root key). Once it reboots, proceed to the next step.
7. Use a filemanager or FTP server to retrieve your root key dump from your PS3 - it is located at dev_hdd0/tmp/eid_root_key. It should be 256kb. Get it onto your USB, it should be in the same directory as your Backuprflash.bin. Rename it to "dump" (no file extension).
9. Start up CEX2DEX again on your PC. For the NOR/NAND flash dump, select your Backuprflash.bin. For the METLDR dump, select your rootkey (file named "dump"). Click on CEX -> DEX, and when it prompts you save the new file as "rflash.bin" and put it onto the root of your USB stick. Your NOR/NAND dump is now fully converted to DEX, all that is left is to flash it back onto your PS3. The filesize for rflash.bin should be 16mb for NOR consoles and 256mb for NAND consoles.
10. On your PS3, use FactoryServiceMode Tool to boot into Factory Service Mode again. On your USB, rename "Lv2diag.self" to "Lv2diag.self.exit" and rename "Lv2diag.flash.self" to "Lv2diag.self". Delete the advance.cfg file from the USB, and put this one onto the root of it: advance.cfg
11. Make sure your PS3 is fully powered off, then plug your USB into the rightmost USB port. Turn on the PS3, and it will begin writing to your NAND/NOR. DO NOT TURN OFF THE PS3!!! If you do, it is a guaranteed brick. Just leave it alone until the PS3 turns itself off, it may take 15 minutes or more. Don't worry if it's taking too long, mine took about 40 minutes to write completely. Once your PS3 has powered itself off continue to the next step.
12. On your USB, rename "Lv2diag.self" back to "Lv2diag.self.flash" and then rename "Lv2diag.self.exit" to "Lv2diag.self". Place the USB in the rightmost USB port of your PS3 (turned off), then turn it on. It should turn itself off after a few seconds. When it turns off, remove your USB and boot the PS3. It should now be out of factory service mode. Congratulations, you are now ready to install DEX firmware. I would recommend downloading and installing this debug firmware, from there you can go to 4.20 debug or whatever other version you want.
-Once you convert to DEX, your console can no longer access the Playstation Network. Your IDPS becomes invalid.
-You cannot data transfer from a DEX console to a CEX console.
-If you choose to install a debug update of version 3.56 or higher, Peek & Poke will be disabled. This will make certain homebrew applications no longer work.
-Most PKGs and homebrew applications will have to be resigned as debug files before they can be installed/run on DEX firmwares above 3.55.
I hope this makes the whole process of converting from CEX to DEX easier for some of you. Remember, this is NOT something that the average jailbroken PS3 owner should undertake. Have fun and be safe