As stated in the title, this mod replaces Ho Ho Ho with Overkill (which is an unofficial name given to the latter track since it was unnamed). The original files were downloaded from a link provided in this post on the Facepunch forums.

Preview:

Notes:

• I think some portions of the track are missing since they are present in the preview video above, but I wasn't able to find them in the music dump mentioned at the beginning of this post. If I do manage to find them, I'll make an update to the mod here. Turns out that the uploader of the video above mixed Black Yellow Moebius in, according to Zdann in the comments below (thanks for clarifying!).
  
• This mod was requested by P.T (note: I don't normally take requests, so this is the exception rather than the rule).
  

Mod Type:
.pdmod (Installation requires Bundle Modder)

Note that for this mod, no bundles are actually modified since Bundle Modder extracts the .bnk file to be modified, executes the modification .script on it, then places everything (both the .stream files and the modified .bnk file) in the mod_override folder (since OVK has permitted .bnks to be used from it). This means that game updates are safe, but you may need to use Bundle Modder to 'refresh' (reapply) the mod after a game update if new tracks are added by OVK (or you won't be able to hear the new tracks). This process is significantly faster than a regular bundle mod application anyway, so it should really be among the least of your concerns regarding updates.

Why is this a .pdmod? Because that's the only way to load a .script that modifies the relevant .bnk file in a way that preserves compatibilty when installing multiple audio mods that modify the same .bnk file. So why does the .bnk need to be modified, anyway? Because the replacement tracks are usually of different lengths, and the game's audio engine does not determine track length by the actual file that gets played (instead referring to the .bnk file for the length), therefore resulting in premature/delayed loops. Shoehorning tracks to fit the original tracks' length is usually not an option. Furthermore, some tracks are partially embedded into the .bnk file, which leads to serious audio glitches occurring due to the mismatched data.

TL;DR:
Audio .pdmods do not cause bundles to be modified and are update-safe, period. Enough of the .pdmod phobia already, seriously - the bundle modifying/rewriting process does not apply to audio mods. Understood? No? Go back and read the above again, and more carefully this time.