The installation will go like this:
If you're under 3.55 CFW/OFW, just update directly to 4.21.1REX
If you're under 4.xx CFW like Rogero or E3, you need to do this:
- Install 999 REX downgrader through XMB
- Once downgrader installed install REBUG toolbox and run it
- Go over the far right side, Enable QA (*this is required)
- Now install REX 3.55.3 over XMB
- Once REX 3.55.3 is installed, now install REX 4.21.1
- Job well done! Welcome to REX 4.21.1
If you under Debug Firmware, you need to convert back to CEX first and activate QA then turn on Debug Update, after that, install REX 4.21.1 under XMB.
yes, only for CEX users, DEX converted consoles need to go back to CEX first.
yes, the 9.99 Syscon Version will trick any CFW (4.21 or 4.30 Rogero for example) to be installed on the top on it without going through Recovery Menu