Before you get started, make sure you tune your guitar down one half-step to (Eb Ab Db Gb Bb Eb).
The entire song is based around 3 simple chords. Those chords are played differently depending on what section of the song you are at, but hopefully this quick video lesson will demonstrate in an easy to understand way, how to play everything.
Besides the verse and chorus sections, Kurt Cobain also played a melodic yet rather erratic guitar solo towards the end of the song. Some of that is not really all that recreatable, but for the part that does contains a definitive melody, I will demonstrate how to play that.
I hope you guys enjoy learning this last hit from Nirvana!