To jam and learn K-Dumen - Nabak chords, your primary focus should be mastering these chords sequence: Cm, Eb, Bb, F, Cm, Bb, Cm and Bb. I suggest starting at a calm pace of 57 BPM, and as you gain confidence, approach the song's BPM of 115. With the song's key of Bb Major, set your capo to fit your vocal range and chord choice.