From alexxoid.com
To update ghostscript package to version 8.70 under Linux Red Hat / CentOS, you need connect an additional repository Black Op. See instructions here.
Download blackops GPG Key.
wget http://blackopsoft.com/el5/RPM-GPG-KEY-blackop
rpm --import RPM-GPG-KEY-blackop
rpm -i http://blackopsoft.com/el5/RPMS/noarch/blackop-el5-repo-1.0-2.noarch.rpm
or
Download the Repository RPM
wget http://blackopsoft.com/el5/RPMS/noarch/blackop-el5-repo-1.0-2.noarch.rpm
rpm -i blackop-el5-repo-1.0-2.noarch.rpm
rpm -i http://blackopsoft.com/el5/RPMS/noarch/blackop-el5-repo-1.0-2.noarch.rpm
rpmforge recommends using yum-priorities and setting their repo lower- in our case, you may need to set the priority higher.
Then run:
# yum install ghostscript
