Fan-run lyric sites often allow you to copy and paste text into a notepad file.
If you don't need to own the file and just want to listen, you can find full playlists on:
Their discography, including lead singles like "That Man Opposed" and "Lover Cop," is available for download on Apple Music and Amazon Music. 2. Streaming & Playlists Download dmtn TXT
Fans often host rare tracks or full sets like dalmalava’s DMTN playlist .
If you specifically need a .txt file containing their lyrics: Fan-run lyric sites often allow you to copy
Your request for a guide on how to could mean a couple of different things depending on your interests.
Since most users searching for "DMTN" are fans of the group, 1. Official Digital Stores Streaming & Playlists Fans often host rare tracks
The most reliable way to get high-quality audio files is through official digital storefronts.