i will ask some stupid question here but what the heck?!

does anybody here know how to decompile the *.rpm file
i mean to torn apart to binary file so that i could modify it.
i want to modify some gnome applications in order to run
the applications. my glibs is not supported by the older
versions, but if i downgrade my glibs much of my applications
would not run.
is there a possibility!~

thanks people!