I saw adrian smith do it for some interview or somthing.Do it every day for an hour...you'll be flying in no time.
Do this everywhere on the fret board.Just pick the note before the 'initial' pull off of each 'flurry'.Use all four fingers to do this exercise since the point is to build speed and dexerty in while using ALL your fingers.Make sure your index and middle finger remain on the fretboard while doing the flurrys(exept when you need to do the first flurry with your index and middle finger obviously).Go as slow as you need to so the notes sound clearley.You might want to do this routine with no distortion(or any exercise for that matter).
E-4p3h4p3h4p3h4p3-5p4h5p4h5p4h5p4-6p5h6p5h6p5h6p5----
B-------------------------------------------------------------------------------------------
G-------------------------------------------------------------------------------------------
D-------------------------------------------------------------------------------------------
A-------------------------------------------------------------------------------------------
E-------------------------------------------------------------------------------------------
E-5p4h5p4h5p4h5p4-repeat------
B-----------------------------------------------
G-----------------------------------------------
D-----------------------------------------------
A-----------------------------------------------
E-----------------------------------------------
Hope this helps somebody!
Later! \m/
Try once,fail twice...