Hi Teresa,
Thanks for writing in with that great question!
You can unregister from a volunteer opportunity by clicking your profile menu in the top right-hand corner and selecting Need Responses. From here you will have a table list view of your responses, once you've located the need in question select Unregister from the Options drop down and Yes to confirm, pictured below:
I hope this helps!
All the best,
Rachel
Teresa Norman
I have signed up to volunteer and now I can no longer do it. Where on this site do I cancel?