Look real carefully in the box. Is there a slip of paper with the TurboTax phone number? Some Costco customers have said there is. If not, we can tell you how to reach TurboTax Support to ask them for a download.
Another alternative is to buy an external DVD/CD drive for around $15-20.
Or to reach TurboTax Support see this FAQ:
https://ttlc.intuit.com/replies/4259363