To everyone having trouble replacing the music, despite having pxtone and saving over the original files, I do have the solution. Check the pxtone.dll file in the main folder of Rockman 7 FC. Make sure it's the same version as the pxtone.dll file in your pxtone program folder. If it's not, copy the pxtone.dll file from your pxtone program folder and replace the pxtone.dll file in Rockman 7 FC. Once you replace it with the current version, you can successfully replace the pttune files in the bgm folder and it will play in the game.
Huh, didn't know that. Tested it and it works, Nice going.