With the new install of openafs 1.4.7, the kernel module will build automagically when the computer is rebooted. 

 Old Instructions - prior to dkms

0. Become root
1. Install the updated kernel-smp and kernel-smp-devel rpms (up2date, by
default, will not install these updates) with the command:
up2date -f kernel-smp kernel-smp-devel

2. Rebuild the openafs rpm
2a. cd to the directory with the openafs src.rpm
2b. For the kernel you wish to build for (list installed kernels with):
        rpm -q kernel-smp
which will give you output like:

kernel-smp-2.6.9-42.EL
kernel-smp-2.6.9-42.0.10.EL
kernel-smp-2.6.9-55.0.2.EL

So, in the above example, I have three kernels installed, and I probably want
to build for the newest one, which is: kernel-smp-2.6.9-55.0.2.EL

2c. Put the kernel version into the rpmbuild command:

rpmbuild --rebuild  --target=`uname -m` --define "build_userspace 0" --define "build_modules 1" --define "kernvers 2.6.9-55.0.2.ELsmp" openafs-1.4.2-rhel4.1.src.rpm

Note that in this command, the kernel version is listed as:
2.6.9-55.0.2.ELsmp
and not: kernel-smp-2.6.9-55.0.2.EL
3. Install the built openafs kernel module, which will be in
/usr/src/redhat/RPMS/i686/
It will be called openafs-kernel-smp and will have version information matching
the kernel in the above rpmbuild command. For example:

openafs-kernel-smp-1.4.2-2.6.9_55.0.2.ELsmp_1

You can list the installed openafs kernel rpms with:
rpm -q openafs-kernel-smp

You can isntall your new openafs kernel module with a command similar to:
rpm -Uvh /usr/src/redhat/RPMS/i686/openafs-kernel-smp-version.rpm