Il Mio Problema
My Mid 2011 MacBook Air battery had started to deterioate and I would only get about 3 hours max.
La Mia Riparazione
I picked up what I thought was the right size pentalobe screwdriver, but it did not fit. Once I bought the right one and a set of replacement screws, the battery replacement went great.
Il Mio Consiglio
Make sure you have the right screwdriver and pick up an extra set of screws. The original screws are some what soft and picking up a nice new set is cheap and worth it.