To delete a member or visitor (soft delete) , you need to go to the profile of the person you want to delete, Click on the edit button and scroll down to the bottom of the page where you see the red danger zone:
Click on the delete member button and select the reason why this person is being deleted:
and click on the delete member again.
The soft delete option will delete a person from a group and the record will got the deleted tab. This person will go to the deleted list that the Senior Pastor or Administrator will see.
If you need to a hard delete (meaning the record will be completed deleted), you will need access. Only Pastor Role and above has that option.