I have a 15-inch Mid 2009 unibody Macbook Pro with a failing battery. I went to the apple store in grand central and bought a Macbook Pro 15-inch rechargeable battery. The sales person there said it would be easy to install and that it was the correct model. So I went home and opened up the back of my computer with a #0 Philips bit screwdriver. I found that I also needed a 1.5mm pentalobe screwdriver to remove the battery. I was then told to follow the instructions on ifixit.com,

Installing MacBook Pro 15" Unibody Mid 2009 Battery - iFixit

These instructions make sense to me but I had a few questions. Will the battery I bought work or do I need to buy a new one? The battery in my computer definitely looks different but if the new one fits and works than I would like to go with the one I already bought. My second question relates to the tool I need to get, a 1.5mm pentalobe screwdriver. Is there a store that sells these? I have checked the most of the computer stores in my area but I will be in New York City at the end of the week. I know I can find them online but I would prefer to find one in a store. What stores in New York City would carry this screwdriver?

Any assistance would be appreciated.
Thanks for reading my long message.