Final Two Achievements Need Help(Anniversary)

So, I have these final two achievements to get in Halo Reach. One of them is an Anniversary achievement, Bounty Hunter. Got get me a Skullmanjaro but headhunter annoys me to no end. The other achievemment is a Defiant one, Don’t Touch That!, and I technically should have this already but it never unlocked. Annoying. With Halo 4 fast approaching and many other games to play I would love it if any of you guys can help me out. Also, of course, I would be willing to lend a hand in helping you out as well in your achievement hunting.

I do have work so the best times to do this would be Friday-Sunday anytime before 4 Eastern Time.