Delete old appointments in bulk?

This is a general usage question. Is there a way to delete a LOT of old appointments at once? My client who is using this plugin has not been deleting old appointments from the records, which is a lot since I installed this in June 2016. I would rather not have to site and delete each one individually. Is there a way I could do it in bulk? If that feature is not available yet, could this be added to an update in the not-too-distant future? After all this time I could wait a bit if it were to be added soon. Many thanks.