movies from LR CC to Classic and mobile, large mobile downloads lrdata

Hi there, 

I have been using LR CC but have now moved over to Classic. I am running out of space on my hard drive and realised I have a 200gb Mobile downloads .lrdata. I presume when I imported raw files into CC it created a copy of these files to send to the cloud? The original raw files are stored in my dropbox. I am just trying to work out how to free up the space and move the images into my LR Classic catalog. 

Any insights would be great

Im just trying to get my head aroud the way it works 🙂