Worked 100% As I Hoped
5 - 10 minuten
I had never replaced my battery in the 4+ years I have owned it, and things were getting pretty frustrating when it wouldn't last longer than an hour before dying (even when using light programs). As a full time student, I was getting tired of not being able to work on things in class before my computer died halfway through the period.
So stupid simple. Breaks my heart to know how inaccessible newer devices from Apple are. With the unibody MacBook Pro, it really did involve just unscrewing the bottom plate, 2 more screws to get the battery out, 2 screws to put the new one back in and the bottom plate went back on. 10 minute fix for anyone. No possible way to mess it up (as long as you don't lose the screws)!
This is not a repair you want to wait on doing. I had noticed my battery losing capacity for a while, but was able to tolerate it for a while longer. What I realized after putting in the new battery was that the old one (which sat directly underneath the trackpad) had begun to swell, and was causing my trackpad to be a little more stiff. A stiff trackpad may be a tell-tale sign of a dangerous battery, so keep an eye on it.