Borderlands

Just a little advice for those having difficulty with Undead Ned.
I could give you the general advice of shoot for his head, having some healing kits, etc. etc., but this is what really helped me.
I died when I was fighting Undead Ned, and it spawned me at the top around where I killed Dr. Ned. When I was going down to where Undead Ned is, I fell until I was one level above where Ned was. It's pretty hard to miss this as you fall through a fairly small area to fight Ned. From this vantage point, I could easily get head shots on Undead Ned, and yet he couldn't hit me at all. I took him down in about a minute while standing there but he couldn't do any damage to me.
Hope that helps, and happy achievement hunting!

Going by the main story,this is the tenth and final mission of the DLC.Here's a list of the missions before this-
1)Welcoming Committee
2)Is The Doctor In?
3)House of the Ned
4)There May Be Some Side Effects...
5)Secrets and Mysteries
6)Jakobs Fodder
7)Hitching A Ride
8)A Bridge Too Ned
9)Night of the Living Ned
**************10)Ned's undead, baby, Ned's undead***********
Objectives-
Dr. Ned killed... again: 0/1
*This DLC took me about 1 hour and 30 minutes to complete