Push very hard on the screwdriver and turn slowly.
Note that the screws aren't straight up and down- they lean over a little bit. (because of the tapered edge)
Where can you buy an extra set of screws for the mid-2009 MBP 17?
It's not 00 it's 0. I was having a very hard time with glasses size screw drivers but once I got this a real screwdriver with this size it was actually quite easy.
It is double zero, philipshead 00.