Here's the steps I take to update my Apache install via src rpms
I get them from:
ftp://updates.redhat.com/enterprise/3ES/e...-57.ent.src.rpm

cd /var/spool/up2date/
wget
ftp://updates.redhat.com/enterprise/3ES/e...-57.ent.src.rpm
rpm -ivh httpd-2.0.46-57.ent.src.rpm
emacs /usr/src/redhat/SPECS/httpd.spec
Change the suexec parameters /var/www to /home
rpmbuild -bs /usr/src/redhat/SPECS/httpd.spec
cd /usr/src/redhat/SRPMS/
rpmbuild --rebuild /usr/src/redhat/SRPMS/httpd-2.0.46-57.ent.src.rpm
cd /usr/src/redhat/RPMS/i386/
rpm -ivh --replacepkgs --replacefiles httpd-2.0.46-57.ent.i386.rpm

If you can find a way to get them from up2date, you don't need to ftp them, so it would be more like this:

> up2date --get-source httpd
> cd /var/spool/up2date/
> rpm -ivh httpd.xxxxx.stc.rpm
> emacs /usr/src/redhat/SPECS/httpd.spec
> Change the suexec parameters /var/www to /home
> rpmbuild -bs /usr/src/redhat/SPECS/httpd.spec
> cd /usr/src/redhat/SRPMS/
> rpmbuild --rebuild /usr/src/redhat/SRPMS/whatever.rpm
> cd /usr/src/redhat/RPMS/i386/
> rpm -ivh --replacepkgs --replacefiles apche2-x.x.x.i386.rpm
>
>