Play Hardcore. Camp your ass off. Use Cold-Blooded so your name doesn't pop up and you can hide easier. In case of enemy UAV, run Ghost, bring a sidearm, and patrol the area for the duration. Or just shoot the damn thing down.
No perks/no weapons:
Play Hardcore. Remove everything from the class but the shield. The game counts lethals and tacticals as weapons here. Otherwise same as before.
Damage absorption/Combat Axe kills:
Play Core TDM. Find a random. Follow him. Distract bad guys. If bad guy shoots you, absorb damage and pray your random kills him. If bad guy shoots random, axe him and giggle.
Not sure what the 5th one was but it was pretty easy.
You know, in Japanese, the Wii 2 would be called the Wii Nii... -NikP1
I came in here to type exactly what advance typed. In addition, for the first 100 kills, I'd strongly suggest running movement perks (LW and ExCon) as well as Tactician (for concussions and shock charges) and Tac Mask. Find an area of the map that you feel comfortable with and patrol it. The shield melee is wildly unreliable and this especially hurts in HC...so concussions/shock sticks are a godsend, assuming you can catch them somewhat unawares.