Both Admins and Co-admins can remove a member from a Circle.
- Open your Circle
- Tap "Menu"(icon with three parallel horizontal lines) at the bottom of the Circle
- Tap "Circle Members" on the general Menu
- Tap "..." on the top right of the Circle Members page
- Tap "Manage Circle Members"
- Tap "Edit" in the top right
Choose who you'd like to remove from the Circle and remove them