Everything is quite simple, head over to http://dk.toastednet.org/ and view the downloads sections for Daikatana, here is a direct link for the lazy:

http://dk.toastednet.org/index2.html

Under the music section all the way at the bottom you'll find Daikatana HQ Music Mod by Poochyfud. Download that. Again here is a direct link for the lazy:

http://dk.toastednet.org/Music/dkhqmusicpack.7z


Open up the 7zip fie and you'll see a data folder. Extract that into your Daikatana installation directory. Something like this:
Steam\steamapps\common\Daikatana\data

Replace all the files in there to get the primo 320kbps MP3s.

Here is a snapshot of the readme file:

Originally posted by Poochyfud:

Just extract this file into your main Daikatana directory and let the files overwrite to replace the 128kbps installed mp3 tracks with 320kbps tracks ripped from the official soundtrack discs! Don't forget to crank up that music slider in the options menu because you won't hear much at the default setting of 30.

E3B was a slightly tricky one; on the CD this is made up of three separate tracks, Iced Passage I & II & Choice of Path, which had to be combined into 1 track for conversion. DM3_death is a shortened version of the longer E3A (Horror Alone on the CD).

A couple of tracks in the original installation, DM1_Riffy and DM2_Forebode have no analogues on the CDs and therefore are not replaced by this pack. The tracks in question are only used in deathmatch levels so for singleplayer or coop mode you'll never know any difference. ;)

Big thanks to the original composers: Will Loconto, Will Nevins, Stan Nuevo, Al Chaney, Bobby Prince and John Romero for making some pretty kickass music; that the masses have not allowed themselves a chance to enjoy it is their loss. Special thanks to Dominus Animae for publishing the soundtrack volumes.

Suck it down (TM) in good health...

-EL POOCHYFUD