Procedure for Exchange 2013 upgrade from cu 8/9 to cu 14

1. download the latest CU update
Note: if you are running a DAG, review this article: How to install Exchange CU updates on a DAG.
http://enterpriseit.co/microsoft-exchange/install-exchange-update-rollups-on-dag/

 2) Execute the downloaded file on the first Exchange server you will be upgrading to CU14.  I recommend extracting to an easy to type folder, like C:\Exch2013CU14
 Note: Be mindful of hard disk space, it may make sense to extract to a folder on a disk other than C:.
 3) Next, CU14 may require that you prepare AD and upgrade the AD Schema for Exchange 2013 CU Upgrade.  That link will help you determine if it’s necessary for you to run a Schema upgrade from the currently installed CU as well as walk you through the process.
 4) Open an command prompt using right-click-run-as-administrator
 5) change directory to the folder where you extracted the CU14 files “cd\Exch2013CU12”
6) type “setup.exe”
7) click ‘next’ on the connect to check for updates screen
8) Once the update portion is complete file copying will begin
9) Setup will detect this is an upgrade, click next to confirm/continue:
10) Next, choose whether you accept the license agreement
 11)  The Readiness Checks will now occur
12) Fix any issues found in the Readiness checks and click retry, repeat this process until the readiness checks complete successfully
13) The upgrade will now proceed through it’s steps, starting with Organization Preparation
14) The upgrade will take quite some time, and then once it’s complete it is recommended you reboot the server

I should have been more clear on my initial statement.  There are no intermediate steps when spanning CUs.  

After installing the updates, a reboot isn't required, but I've always done it to make sure everything is working correctly.

Thanks Scott and Belal.

Belal, you have mentioned that the following link will help me determine if CU14 will require me to prepare AD and upgrade the AD Schema:

But the only comment I see in that article is as follows:
"If you are installing Exchange 2013 SP1 then you need to first prepare the Schema and AD for Exchange 2013 SP1."

We are on CU 8 which I believe is post SP1.
So does that mean that I will not be required to prepare AD and upgrade schema?

Solution provided.

I'm curious; how long did the CU14 update take?

I'm currently running an update from CU6 to CU14 and it has been going for 15 hours now but isn't hanging (mailbox db is approx 650GB).
Current status is 57% of step 14/18.

cheers