I did the repair using a Ifixit guide. Took about 1.5 hours and got to clean the inside of the macbook too. I had quite low expectations for the sound quality but I must say that I was happily surprised! They are almost as good as the originals (which aren't great to start with though). All in all it was totally worth it and i would definitely recommend doing the repair yourself! Good luck!
The left speaker has good sound. The right speaker volume is very low. I'm disappointed