Login into your Blackboard, then scroll down to Control Panel which is in the left bottom. Click on Users and Groups and select Users.
And then you will be directed to a page as shown below. Select Not blank in the circled area and click on Go button.
All the students who enrolled in this course will be shown below. Check the boxes to select the students that you want to remove.
Click on Remove Users from Course button to remove the selected students from the course.
Click on OK.
You will receive a message saying that enrollment has successfully deleted.