While in the Homebase view, click on the row for the client. Then right-click and choose Delete.

Delete is not an option - it is grayed out.  Any other way?

Highlight the return in homebase and click the “delete” key on your keyboard 

Go into the 21Data folder and delete the file and the cache file.  Then from within the program click on the Homebase drop-down menu and choose Homebase Maintenance. Choose the 21Data file, if it's not already chosen, and Run the maintenance. This will update your homebase against the files in that folder and give you an option to fix the discrepancies.

Hitting the delete key sure seems like a lot less work.