Update Kernel on Linux Redhat / CentOS

Update Kernel  in Linux (Redhat / CentOS 5&6)

I would like to upgrade kernel without compiling from source code i.e. binary upgrade. How do I perform the actual upgrade of the kernel in Linux?
You need to compile kernel only if:

•  You need custom made kernel for specific task such as embedded kernel.
•  Apply third party security patches.
• You need to apply specific patch to Linux

Upgrade of the kernel in Red Hat enterprise Linux version <= 4.x

If your system is registered with Red Hat Network (RHN), then you can use the 

up2date command as follows:
    # up2date -f kernel


For SMP kernel (multi core or multiple CPU) use command:
   # up2date -f kernel-smp

Upgrade of the kernel in  CentOS / RHEL 5 &6

Use yum command to upgrade kernel:
    # yum update kernel

If you have downloaded RPM file use rpm command
    # rpm -ivh kernel*