Just so you know Mint 16 ended support July 2014. If you upgrade / re install to 17 you should be ok for 5 years. 17 is a long term support version, 16 was not.
That being said. Goto dropbox.com > download. Download the proper .deb for Ubuntu. When downloaded (i think this works in mint) double click the downloaded deb, your package manager should take over from there... it will require your sudo password to finish. That will install the dropbox client to your computer.
Last edited by Tadaen; 10-11-2014 at 11:45 AM.