It is simple to Delete a Group Member on WordGo.
Simply tap the 'Group Details' button (three connected circles icon) near the bottom left of your home screen. You will see a list of everyone in your group with an 'X' beside their names. If you tap the 'X' this will allow you to delete the Member from your Group.
If you have any further questions please raise a ticket here to contact a WordGo customer support agent.