I did it last year on my 2012 rMBpro after it have been complaining about servicing the battery for about a year, and while it wasn't a walk in the park, it all worked out great.
Tip: there are 2 ways to replace the battery.
One is by following the official iFixit etc instructions where you remove absolutely everything before you peel off the battery with acetone.
The other is by immediately peeling off the battery right away. In that case, you have to be careful that the acetone doesn't flow onto the speakers (because they'd melt.) That's the way I, and many other with me, did it. It still only took me about 1 hour to get everything back up and running.