You can easily rename the content in your class. Here is how:
Click on the three dots before the title of the content you want to change, and select "Rename"
After changing the name, press "Save"
From now on, all students in this class will see the new name. Note: these changes are only visible to the students in this particular class. If you use the same content in a different class, they will still see the original name.
After changing the name, you can always revert the names to the original names by clicking on the third icon.