I managed to change the battery in the MacBook Pro, and it wasn’t that hard.
There are plenty of batteries to choose from, and they may be from the same factory for all I know. I opted for this one, which was not the most expensive one, but not the cheapest either.
It comes with all the tools and stuff you need. And printed out instructions, although I’d encourage you to look through some of the many videos on YouTube about changing batteries.
Essentially it was pretty easy. Just be careful and follow the instructions.
I thought the trickiest part would be getting the old battery loose from the computer, but even that wasn’t so bad. Just take it easy while you also apply pressure, and you’ll be fine.