Download SRPM into a directory of choice. Generally files out to go into:
/usr/src/redhat/SRPMS
Then run:
rpm --rebuild <file>-<version>.src.rpm
This will then build the new RPM. Everything will then happen automatically, and the newly built RPMs will go here:
/usr/src/redhat/RPM/<cpu-type>
If the configuration file needs to be changed then run:
rpm -i <file>-<version>.src.rpm
The spec file will be extracted to:
/usr/src/redhat/SPEC
Generally it would be called:
<file>-<version>.spec
Changes can now be made to the spec file. Once the changes are complete the RPM needs to be made using it:
rpm -bb --clean --rmsource <file>-<version>.spec
If the build goes ok, the file will end up in the normal location:
/usr/src/redhat/RPM/<cpu-type>
Building a Kernel RPM (build UP and SMP Kernels)
rpmbuild --target i386 --with up --with smp --without BOOT --without debug <spec file>