This song is easy to play.
Tuning Eb
Eb Ab Db Gb Bb Eb
Chords (in Eb tuning):
Ebm [022000]
Ab [577655]
Gb [355433]
B [x35553]
[ Tab from: https://www.guitartabs.cc/tabs/n/nirvana/dumb_tab_ver_3.html ]
Main Riff:
Ebsus4 Ab5 Gbsus4 B
---------------------------------------
--------------------------------5------
-----2---------2------5-------5-5------
-----2------2--2------5-----5----------
---------0----------------3------------
--0---------------3--------------------
Chorus: Eb5 [022X00], Gb
Bridge: Bb, B
I doubt this is fully correct, but it is a tab for this song,
and it does get you somewhere.