ftp and firefox for windows

I posted this and was told it was ;posted, but then I got a not found error when I tried to view it, so I'm trying again. I set a site to use firefox as the default app for ftp not realizing ftp support was removed from the browser. I have been trying to get the dialog back that will allow me to change it. I downloaded filezilla to use for ftp. However, I am unable to get the dialog back that will allow me to change apps. Can someone help me get the dialog back? And, before anyone suggests it, resetting firerfox to the default settings is not an option.