For this tutorial, I assume you have already installed and configured Dropbox on your linux server.
If it is not the case, follow how to install and configure Dropbox on linux server tutorial here, https://creativcoders.wordpress.com/2014/06/04/install-dropbox-on-linux-debian-7-wheezy/.
First, you have to dissociate your machine from your Dropbox account by following these steps here: http://www.wikihow.com/Unlink-a-Computer-from-a-Dropbox-Account.
Now, in your console, follow these steps:
You should now see output like this
This client is not linked to any account... Please visit https://www.dropbox.com/cli_link?host_id=7d44a557aa58f285f2da0x67334d02c1 to link this machine.
Dropbox will loop on this message, copy this link, target it in your browser and log in to your dropbox account, you will see a confirmation that your machine has been linked to your dropbox account.
PS: MAKE SURE TO NOT STOP THIS LOOP ! Copy the link by right clicking, but don’t press ctrl+C, it will stop the loop and your account will not be logged.
You’re a champion ! Now start dropbox server and it’s over :).
python ~/bin/dropbox.py start