In order to test your FTP you will need to have a device that outputs in .FIT or .TCX file format (simple cycling computer) or a Strava account.  

Simply do the FTP Check as prescribed over a moderate (20 minute) climb, and upload the file from your computer in your VeloPro account online.  Alternately, if you have a Strava account, it will automatically push to VeloPro from Strava (if you set it up that way).  VeloPro will estimate the power from your speed, elevation, weight, and bike weight.