Deleting all files under a component from the repository

I don't think there is a way to delete all the files in a component in a single shot, but the article you are referring to shows how you can delete a file that you have checked in.  Here is another article (https://jazz.net/products/rational-team-concert/features/scm/), which also has a video on how to get to the "Delete Content Menu". Look for section "Full administrative control to delete contents from source control". You must be JazzAdmin and member of the project area to be able to perform this operation. The "Delete Content" action will let you delete any intermediate state of a change set from the repository. I think you will need to repeat this operation on each file that you wish to delete.