Changing a Mac Book Pro battery is easy with Ifixit! Don't pay someone else!
Mac Book Pro 2009 battery not available at Mac Store. I found a "new"one on this site. It was more expensive than other options on the internet, but it was "authentic".
Perfect installation due to the tools that I fix it said I would need and the excellent detail step by step instructions. I am so impressed with their detail! Post installation,
I couldn't be more satisfied with the installation. Post installation, I am a bit concerned that this battery might have had a lot of shelf life and I might not get the battery juice out of it that I hope for.
Ask I fix it before purchase what kind of battery life you should expect out of this purchase. Definitely buy the tools that they recommend.