Audio modding; changing loop points / adding longer tracks

Hello all, I had a quick question.

I’m looking to just replace some songs in the Original OST DLC and my plan was just to make edit the new songs to be the same length as the old one, I don’t want to mess with loops.

Am I able to just edit and leave in the new songs in the same time range so i don’t have to mess with loops?

Example: Old Song = 2 minutes, New Song = 2 minutes, or Old Song = 30 sec, New Song = 30 sec.

Also, Do you still have to edit the music_dlc_classic.pck.3.x64 file afterward?

INCREDIBLE, ABSOLUTELY INCREDIBLE.
There are absolutely no GUI tools at the moment that can manipulate anything with the bnk's or even extract pck's with bnk's in them, but with you're incredible guide, there's absolutely no need to even have one.

I'm making a mod for Elden Ring Network Test to add Breath of the Wild music into it, and it's been working perfectly. And the same process will be done once the game is fully released to change the whole soundtrack. Thank you so much for this absolutely incredible guide on how to do this, I wouldn't have even had a shot at this without it. I can't thank you enough man, this is just incredible.

NEGAARMAX it took months to figure out, it was strange at first. For ev, tools not gonna help much, you have to do hex editing more (or just hex-edit everything, even .wem file himself).
What and where to hex edit differs per file.

E.g. main concept:
You want to change audio in ".pck.3.x64.en" (3.6MB) from "...\streaming\sectionroot\sound\wwise"
You must hex edit ".bnk.2.x64.en" (124KB), ".pck.3.x64.en" (1KB) "..\sectionroot\sound\wwise"

After modded ".pck.3.x64.en" (3.6MB) from "...\streaming\sectionroot\sound\wwise".

New header data goes to:
".pck.3.x64.en" (1KB) in "..\sectionroot\sound\wwise"


Audio files data chunks goes to:
".bnk.2.x64.en" (124KB) "..\sectionroot\sound\wwise"



If your modified file audio data was in ".bnk.2.x64.en" (124KB) "..\sectionroot\sound\wwise" (is checked by game), you must edit and replace with new (from modded .wem).
Exactly where, and how much data.. you just need to find yourself by checking unmodded files with hex editor. If you want to do project (like translation), is gonna be a lot of time figuring out file by file.