I havent downloaded a fortec, but Ive worked with about 5 or 6 others.
Its pretty easy
-hook computer to receiver with a RS232 cable (some need null mdoem cable...the manual/manufacturer will know)
-there ususally is a program that you open up and pick the sofware that you have
-hit OK and it downloads to receiver
It takes like less than a minute in a lot of cases
The fortecs are straight thru.. as far as I know, it only needs pins 2, 3, and 5 connected (TX, RX, and Ground) but as long as at least those three wires are straight 2 to 2, 3 to 3, and 5 to 5, it should connect.