I have recently migrated my in house Exchange 2003 to Google hosted email. I would like to stop exchange with the least amount of effort.
Microsoft recommends all of this: http://support.microsoft.com/kb/833396 but I'd say that seems a bit too complicated. I was thinking of just disabling the services.
So the question is, if I want to stop exchange this way, which services can I disable without affecting my active directory while still stopping exchange from running?
DO NOT JUST STOP THE SERVICES! The proper way to remove Exchange 2003, if you are fully done with it, is to uninstall it from all Exchange servers in your environment. Exchange is an application that very closely integrates with Active Directory, and just stopping the services will leave a ton of metadata around in your AD. Follow the steps in the following article to fully uninstall Exchange 2003.
How to Uninstall Exchange 2003
The article you reference is good in case the uninstall is failing and you need to manually uninstall it. I have seen the uninstall go really smooth, and have seen it fail miserably. Either way, make sure you fully uninstall it using the manually method if needed.
Assuming there truly isn't ANY reason for Exchange anymore:
The question is because you chose to install Exchange on a server that does additional duties such as a DC, correct? You won't break anything by dismounting the databases and simply stopping the Exchange related services. You might get warnings and errors inside the event viewer logs wondering what is going on, but it won't break AD. Make sure you set them to disabled as well so that they don't start on a reboot.
However, there's a reason why Microsoft creates KB articles and recommendations. It would be wise (and good practice) to follow the article and clean up the server so that you aren't sifting through eventvwr logs in the future.
This will also make sure AD is cleaned up if you ever do decide to reintroduce an Exchange server into the domain.
Just follow the blooming best practices from the vendor. They're there, written in black and white - I don't seen an addendum that says "Or, just disable a load of services if you don't fancy following the above."
Or, to clarify, you may be putting yourself into an unsupportable situation.
Yup. Uninstall properly. When you run the installer on the last server, you'll get the option to remove the org. It'll then tidy up the Services part of Configuration partition in AD. Simples.