MacBook Pro screwdriver size

[Cognizant]

What is the size/type of screwdriver I would need to remove the back panel on a unibody 2010 MacBook Pro?
I just ask because I may upgrade my HDD and none of my screwdrivers fit.

[ethanf93]

According to this: http://www.ifixit.com/pdf/ifixit/guide_4311_en.pdf you probably need a very small Philips screwdriver - "Phillips #00 Screwdriver." (this PDF is for the LCD - but it does show opening the back)

Unfortunately Apple does not like seem to particularly like consumers doing anything other than consumery things with their products.