SELECTED ANSWER
replied on September 7, 2017
Ok so what will need to happen is create a dropdown and assign it the class 'hidden'(advanced tab). use your lookup rules to populate it with the values you want in the dropdown.
Next I will need the source html for the check box. Go into preview mode in chrome, right click the other option box and select inspect. In the window that opens part of the code should be selected, expand the elements around that one by clicking the triangles and then screen shot the code for me.
Upload the screenshot in your next message and when I have a sec ill write the script you need to override the checkbox.