Fred, I don't know if Ride With GPS (RwGPS9 has the ability to edit (crop rides), but I know for sure Strava can crop rides, particularly when one forgets to turn off the GPS. The free version of Strava can do this. Once you crop your ride in Strava, you can export the file and import that file to RwGPS.
Disclaimer: I have not used RwGPS for tracking my rides so I don't know if they have this feature.