Achilles Pinky

Hi Guys,

I just started to work through Troy Stetina's "Speed Mechanics for Lead Guitar" and the
beast below has brought the whole show to a stand still.

pull off
E -----4 ---------- 5---

where I am supposed to use the ring to pin the string and the pinky to pull off.
Also, this has to be repeated on all the strings.

The problem is that I am invariably pulling the whole string rather than doing a "pull-off".
I find that when I start the pull off, the ring finger, rather than pushing the string up, starts to pull it down.

Are there any excercises that can help fix this annoying problem.

Thanks
Vic