www.bungie.net | halo.bungie.net | bungiestore.com
Hello! I'm a male!
Just do them on normal
Yeah. Normal. Each takes about an hour and a half to complete.
I'm 23, I have a house, dog, girlfriend, job and I have no interest in any fanboyism so if you're thinking about sending me a childish PM, don't be surprised when I don't call back.
If your competent then you can do Solo Heroic in about half an hour but to play it safe go for normal. An hour per achievement isn't bad and if you've got buddies then it goes a whole lot quicker.