• Mega Man 8 will have japanese voices in game
  (for the opening and anime videos see the Guide below)
  
• Mega Man 8 and Rockman 8 will play Brand New Way as credits music followed by the instrumental theme
  
• Credits music from Mega Man 8 in Music Player will play the full version of Brand New Way
  
• Selecting Japanese language in the collection Options (for playing Rockman versions of the games) will still keep the HUD in English
  
• The disc file are now password free! You can freely extract and mod its contents!

First, go to the folder C:\Program Files (x86)\Steam\steamapps\common\MegaMan2 (or whatever directory your installation folder is), and rename your original disc file into something else, just for backup purposes. You can rename it to disc_original. Then, download the mod disc file https://drive.google.com/file/d/1pfdETlIyc1_w4fyMWBqmAyF8SF186SSt/view?usp=sharing and place the file in the same folder. And you are ready to go. :D

Thanks to the discovery of the encrypted password from the disc file, now it's possible to access the game files! With this you can easily extract and mod the game. New possibilities have been opened. If you want to access the game files, first download a program that can open compressed files, like WinRAR (for free) for example. After that, go to the game instalation folder and rename the disc file to disc.zip, and extract it with WinRAR. Now you will have access to all of the game folders and files. Just remember that the files must be compressed again with the ZIP extension, in order for the game to read the file. And also change back the file name to disc.

A special thanks to Nico, for kindly sharing the link to the forum (now closed) where the tool to remove the password from the disc file have been released. So I could finally be able to create the mod the way I intended years ago.

https://steamproxy-script.pipiskins.com/sharedfiles/filedetails/?id=1371101714