Autoscroll page for Pick, group, rank question

Hello,
I have a Pick, group, rank question that has about 20 items. It's extremely difficult to drag the item to the box because the page doesn't scroll down when you move the item. Stacking items is not an option because participants need to see all the items at once....
I think adding the CSS code is the only way but I don't know how
I found an answer here with using the jQuery but I'm really lost... Would anyone please help? How do I build the code? how to I append it?
Thank you!