1. Use below yum command:
sudo yum -y install openoffice.org*
2. Download rpm file from http://sourceforge.net/projects/openofficeorg.mirror/files/4.0.1/binaries/en-US/Apache_OpenOffice_4.0.1_Linux_x86-64_install-rpm_en-US.tar.gz/download
and follow the instructions mentioned @ http://www.openoffice.org/download/common/instructions.html#linux-rpm
Another download link http://www.openoffice.org/download/other.html with language specific installers.