Replacement music on his own. (Need for Speed: Carbon)

Disable the in-game music, turn on a playlist, it's simple.

Here:
Spoiler

Zenturo
This is for Most Wanted. For Carbon this app will not work.

-VLD-
Profi 80 lvl

Horeus
It is possible but only through Hex Editor.

Ilya White
and how exactly can you replace the music via this Hex editor