we will use ELRepo to install kernel

1. rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org

2. rpm -Uvh http://www.elrepo.org/elrepo-release-6-6.el6.elrepo.noarch.rpm

3. yum --enablerepo=elrepo-kernel -y install kernel-lt

4. vi /etc/grub.conf

5. reboot