To use FT Remote with WinSCP, you need to use the latest Version 5.2.2 and install the current .Net Library (.NET assembly / COM library) from the WinSCP Website (Copy the .dll file into your WinSCP Directory).
Then Copy the WinSCPRemote.exe into your WinSCP Installation Directory and start the Program with the following Parameters:
-p Port Port on which this Remote Listen
-u User Username for Authenticate to this Webservice
-w Password Password for Authenticate to this Webservice
-d Directory Download Directory
Then you should be able to connect remotely to your WinSCP installation and start Downloads.