doctor who - In what ways can Daleks be killed?

In a 2005 episode the Doctor says that if the humans focus their fire around the eyepiece of a dalek then they should be able to incapacitate it:

The Dalek's surrounded by a force field. The bullets are melting before they even hit home, but it's not indestructible. If you concentrate your fire, you might get through. Aim for the dome, the head, the eyepiece. That's the weak spot.

_{-- Series 1 Episode 6, Dalek}

And we see this done in a later episode. However during the battle of Canary Wharf, at least fifty soldiers and at least twenty Cybermen all focus their fire on the Daleks, and some of the humans are wielding weapons that the Doctor modified and we see disabling Daleks earlier; however in that scene not a single Dalek even seems mildly interested in enemy weapons.