Well you don't even need ninjhax anymore honestly, yes that firmware is perfect for installing CIAs, you can use rxTools to downgrade MSET and get FBI going and if you want you can use gateway launcher to create an emuNAND (you don't need the gateway to do this) and you can install any CFW you want (I recommend Cakes personally) there are many guides including mine, but that's currently in overhaul so I won't recommend that atm hope this helps