Plz help with ISO file shrink/burn to dvd

[1$tkobefan]

Hello, every1. So i'm on here cuz this dvd shrink/ dvd decrypter/ daemon tool stuff is driving me crazy. All i wanna do is shrink the 8gb file down so I can have this navigation disk for my car, that I downloaded from a torrent. The torrent was originally rar., I used winrar to extract it, downloaded daemon tool so I could have the virtual drive, decrypted it with dvd decrypter & when I try to burn it with dvd shrink I get an error message. PLEASE help. Thanks.