Once you have downloaded the CBS All Access app, launch the app on your iPhone or iPad, then follow the steps below:
 
Existing subscribers:
1. Download and launch the CBS All Access app.
2. Select "Sign In".
3. Enter the email and password you used to sign up for CBS All Access. If you subscribed to CBS All Access via your Apple TV/iTunes, you can also select "Restore Purchase" at the bottom of the screen.

New subscribers:
1. Download and launch the CBS All Access app.  
2. Select "Join Now & Get 1 Month Free". 
3. Enter your name, email address, and password on the sign up screen.
4. You will then see the subscription plan offer. Select "Subscribe".
5. Confirm your information and select "Confirm".

You're now ready to stream CBS All Access!