You'll need to create a new instance of FTPConnection, assign it to a variable, myFtpConnection, and then set the properties on that variable.
Dim myFtpConnection As New FTPConnection
myFtpConnection.ServerAddress = "ftp.myserver.com"
myFtpConnection.ServerPort = serverPort
myFtpConnection.UserName = "username"
myFtpConnection.Password = "userpwd"