The original battery wouldn't hold a charge.
Wonderful. I second the users that point out that you must go between the rubber seal and the metal case when prying up the screen. I also found very worthwhile to purchase the simple $3 metal spudger. It allowed me to slip farther under the screen's edge to pry the screen up. After that, I say just be patient and everything goes according to plan just as the directions say. Only other hiccup was that when soldering the top of the battery terminals, I found it a little difficult to heat up the solder through the pinholes and under the ribbon terminal. As a solderer I was not pleased with my work, but the thing fired up and works great. Thanks for the battery and directions and tools and everything. A magnificent job.
Buy the metal spudger, it's only $3 and helps so much getting the screen off.
Also, like others said, make sure to slide the spudger in between the rubber seal and the metal case, and try to pry under the seal, not on it. When I pried on the seal I beat it up a bit.