How do i change sound files for Supertouring 1.6/British Super Touring Cars 1.6?

[Dan Marr]

Please help, i am changing the sound files to the Race 07 games (Personal use only at the moment, without doign disk checks and permission of the person whom made the mod) and it isnt working, i had manages to change the idle sound and the startup sound for the cars without sound files specifically for them