I have a sub-folder in Dropbox Family containing 180Gb of family photos. I would now like to promote it from being a sub-folder to being a root level folder. If I make that change on the Dropbox website, will each PC in our family then synchronise by deleting all files from the sub-folder and then downloading them all again (will take a very long time)? Or will each PC simply move the files without deleting/redownloading (much quicker)? What is the quickest and most effective way to make that change?