is the source extracted?
If so you'll probably have a /usr/src/linux directory (or something similar)
if so change to that directory and do "make config", "make menuconfig" or "make xconfig"
each of these programs allows you to configure the kernel before you compile it....
for more information about compiling you kernel..
If the above directory does not exist u'll need to extract the rpm, this can be done using the rpm program, kpackage or various other tools