Hi,
no, you cannot by and large de-compile. In order to edit your code you need the source code, you edit it
and then a new 'compiled' version is made. Without the source code you can do nothing.
If you were writing a wizard for Mach4 to sell you would not give your customers the source code,
just the compiled or executable code.
You might ask NFS for the source, I suspect they consider it proprietary code in which case they'll say no.
Craig