Spartan 085

As far as the Annual achievement, I'm not quite sure. I haven't even tried for said achievement so I won't be much help to you.

The Lightswitch achievement however is simply getting to the rank of Lieutenant on the new EXP progression system. It's nothing different from the older system besides being able to have ranks in Social matches. To get to Lieutenant, you need to either have a true skill rank of ten(10) or a total experience(number of wins) of seventy(70).

As I said, the system isn't really any different from when Halo 3 first came out other than the fact that you can get rankings in Social games. In the end, it just all depends on you. To get that experience up faster, I'd recommend playing Bungie's Double XP weekends when they have them because each win will net you two(2) points of experience rather than the one that you'd normally get. They normally offer some fun maps and match types to play like Grifball and Team SWAT and the like. You should be at the Lieutenant rank in no time.