Master Data Services Configuration Manager - An error on deleting the master database services databases and websites

Problem: 

During the experimental process, I have created several master database services databases and websites from the Master Data Services Configuration Manager GUI. After everything finally works out, I like to just keep one copy and delete the rest. How do I do it? The only source is from the Microsoft to suggestion uninstalling the Master Data Services.

http://msdn.microsoft.com/en-us/library/ff487065.aspx

So I did it. This time, the IIS part is OK. But when I try to create a MDS database with the previously used name MDS. I got an error message. So the earlier names were not removed when the MDS feature was uninstalled.

Solution:

The MDS folks stated in their website (http://sqlblog.com/blogs/mds_team/)

.....Important   If you do not at least connect the new MDS Web application to a database, you'll run into problems when you select the site again. It will display the message that the site has no MDS Web applications, even though you created one. You must use IIS Manager or another IIS tool to delete the incomplete MDS Web application. Then add it to MDS Configuration Manager, making sure to connect it to the database this time, and click Apply. If you do not delete the incomplete MDS Web application before trying to add it again, you'll receive the error message "An unexpected error occurred: Object reference not set to an instance of an object."........

So how to use IIS Manager to delete the incomplete MDS Web application?

http://technet.microsoft.com/en-us/library/cc771205(v=ws.10).aspx

I delete all of them including the default one.

For the database part, I finally find they are in the SQL Server as regular database after creation on the Master Data Service configuration manager. So I backed them up first and then use the name MQS for a new database. It is OK this time. Now the database and the web application are fresh.

Now the beautiful screen with one database called MDS and one website application linking to the database with the default URL.


So, in retro-prospective, I think that I do not need to uninstall the Master Data Services. I just need to delete the web applications from the IIS manager and the MDS databases from SQL Server. Then I should be able to have a fresh configuration.