Blindwrite 5

I have Blindwrite Suite ( i think) and i want to pdate to Blindwrite 5. I think it said that u can for free if u have the previous version (at least you should be able to). I have searched and found some random files but im really stupid so i didnt exactly no what i was doing. Can someone give me the file or wateva to upgrade (if it exist) and direct/exact instructions on how to install it or wateva. Thanx!!