Which is more pleasant than the Norse method of dealing with missionaries... ;-P *** To address your actual topic, are we thinking of the same thing here? I've always heard that the Norse didn't have "vampires" in the regular European sense, and that their "vampires" were just a standard draugar that preferred to drink blood.
In that case, the folkloric technique was the same for dealing with any other draug: behead it and then either get between the head and the body before they both hit the the ground...
...or, possibly MORE difficult, that you didn't need to do anything past beheading it, but you had to use a specific weapon to do the job...