How do I completely remove a Welders qualification for a process he no longer uses so he doesn't show as expired?

To do this you must first delete all WPQs for that welder for the process. Then Open the welder and select the "Continuity" tab. Then here delete all continuity entries (rows) for the given process and save the welder. Now the welder is no longer qualified for that process and will not show as expired for that process.