In most cases users will self-enroll to your courses. However occasionally you might need to manually enroll a student to one or more courses.
Here is how you can easily accomplish this:
1) When in admin mode click on the "Learners" option in the admin menu.
2) Find the record of the learner you would like to manually enroll to a course, hover your mouse over the "more..." button, and click on the "enroll product" button.
3) In the pop-up sideform that shows up, select the course from the relevant list and give a price (this is the price you are selling the course to this specific learner only - it could be of course the original price of the course). You can write also a small justification if you want. Click "Add" when you are done.
That's it! Nice and easy!