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
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
I would recommend that before you go thru these steps that you perform a full backup of the farm, just in case (Better to be safe then sorry) for those steps please see the following blog http://blogs.technet.com/b/schnood/archive/2011/04/19/simple-sharepoint-farm-backup.aspx
EXCELLENT Artcle ! Very nice ..