no
no a lightsaber would not kill superman
Sure why not Superman would be able to handle the heat of the lightsaber!
Kryptonite
Presumably any superhero could if they had Kryptonite.
Superman must fly him to the air and punch him into space and let Wolverine lose his powers and let him die.
No.
superman killed badguys but not the inocent
You could make a lightsaber,but it we'll probably take many years or it couldn't even happen.
kryptonite
Anyone who has kryptonite and exposes him to it.
Metallo has tried in Superman/Batman: Public Enemies
In the 2013 film, Man of Steel Superman was forced to kill Zod.In the 1980 Superman II, after being stripped of his powers, Superman breaks his hand, throws him into a wall and he falls into a unknown mist. It is unknown if that actually killed him.