From Workhub: 

From your Admin Dashboard, click on the Online Training component

Select the Course you want to grandfather training results for, then click on the first lesson in that course. 

Once you click on the Quiz Questions tab, you will see a button in the top right corner that says Enter Class Results.

This will bring up a pop-up box. Here you can click Add Workers to Class to select workers and add them to this class.  The class is the list of the workers that you want to grandfather in or attending the in-class training session. 

Once you've set up your class, you can begin entering the date in which workers completed training and their pass rates. 

Once your results are entered, you can Submit Class Results. 

Lastly, head to the other lessons in that course and you can pass the same class you created.