UPDATE: After discussing this with some colleagues we figured out that even after disabling the features you will still require an Enterprise License and ecals, because the Enterprise services are still functional in the background ie InfoPath.
Hey again, so you say that you no longer want the enterprise features and want to disable the features and get rid of the licensing fee's. My first comment is consider this very closely as it could have user pains, not that we should break anything (But it could happen so tread carefully) but that once a user get's used to having something they do not want to give it up.
But if you do your due diligence and still feel that it is worth getting rid of them then read on.
Here are the steps you would need to perform to be able to disable all Enterprise features.
To remove the Enterprise Feature from all Sites and Site Collections and your farm, please perform the following steps
Create a list of all the Site Collection and Sub sites that are using the enterprise feature "Office SharePoint Server Enterprise Feature".
Then either run the following command or batch it using one of the following commands.
For Site Collections
Stsadm –o deactivatefeature –id "8581a8a7-cf16-4770-ac54-260265ddb0b2" –url <URL of Site Collection>
b. For Sub Sites
Stsadm –o deactivatefeature –id "0806d127-06e6-447a-980e-2e90b03101b8"-url <URL of Subsite
After running the command or batch I would then go thru and insure you have removed the feature from all Site Collection and Sub sites
Navigate to the Farm Features page in Central Admin -> Applications, and then disable the farm-level Office SharePoint Server Enterprise Feature