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. All you need to do is follow the directions, it's really simple. Nothing related to 4.3 is officially stable to my knowledge, but most 4.3 ROMs are running extremely well for most. If you're looking for something pretty solid on 4.2, Slimbean and Carbon have pretty solid stable releases for this device
. Though, everyone's idea of stable seems to differ a bit. 4.3 is damn close in my opinion-very few bugs left and none of them major imo. If I'm not mistaken, it's 9.18 and 9.20 that no longer allow the bootloader to be unlocked. I don't remember the build date as I haven't been on stock for quite some months. If you find that you can't unlock the bootloader, there's a couple of solid stock variant ROMs to choose from. But if you're not on 9.18 or 9.20, you should be good. You can definitely still root though! Good luck, welcome to the HD and if I can help with anything, just lemme know. The devs and community for this device are truly awesome.