Screw Extractor

[Mike Razor <mrazor@kih.net>]

Who can tell me how these things work.  I have a bleeder valve
sheared off flush with the side of the caliper.  There is a
hole in the middle that the #2 extractor fits in.  There is a
picture of a drill on the box set of extractors.
1. Which way do I turn the drill (forward) (backward)
2. How much pressure
3. Am I suppose to chew the screw out or bite into it and back
it out
HELP!
MIKE R