Navigate to the assignment and click on the upload button.
Enter a title and paste your text in the text area.
Click on show preview.
If lists are used in the assignment, then you'll see statistical information. They will also be shown in the preview: a tooltips will show more information why a word (group) is highlighted.
Students can go back to their text to edit out any mistakes.
If he/she is happy with it, then they can submit their text for good.