No, you can't install CFW directly. You will get a corrupted error. Just faced this throwing a 1TB in mine.
What you're going to have to do is find the HFW firmware that's 4.88. Make sure the controller gets unplugged as soon as you start flashing (the ps3 reads that first for some reason). Then jailbreak via the HFW THEN you can install Evilnat.
That's my suggestion after spending 3 days figuring it out.