Step 1: To assign a different version of a test to different students, first create your two different tests.
Step 2: Click the blue arrow on either test and choose which class you'd like to assign to.
Step 3: Click the class you'd like to assign it to and you'll be led to a class list.
Step 4: Select the test name from the dropdown and press "Apply". You will see one test assigned to everyone.
Step 5: Find the student or students you'd like to assign a different test to and click the "x" in their row.
Step 6: Select a new test from the dropdown and press save!