deleted reseller, files not removed

Hello,

A long time ago (about a year ago) I removed a reseller from a server. The reseller had hundreds of domains (I moved it to a dedicated server).

The problem is that I have found that there are still many files from those domains in the server. Not www files, but all awstats logs, valiases, localdomains, vdomainaliases files where not deleted back then.

Worst thing of all is that they where assigned to another domain!! Today, when I deleted that domain is when I found out about all of this.

How can I remove all those files? They all have the same user (well, right now they have a number as a user since I removed the domain they where assigned to). Why did WHM not remove them before?

Thank you