My Macbook pro won't let me authorize it, it says that i have too many devices when clicking manage devices I only have 4 what do I do?

You must have five already. Deauthorize All then reauthorize the ones you have.

De-authorizing Computers (contributed by user John Galt)

You can de-authorize individual computers, but only by using those computers. The only other option is to "de-authorize all" from your iTunes account.

1. Open iTunes on a computer

2. From the Store menu, select "View my Account..."

3. Sign in with your Apple ID and password.

4. Under "Computer Authorizations" select "De-authorize All".

5. Authorize each computer you still have, as you may require.

You may only do this once per year.

After you "de-authorize all" your authorized computers, re-authorize each one as required.

If you have de-authorized all computers and need to do it again, but your year has not elapsed, then contact: Apple - Support - iTunes - Contact Us.

For more information on authorization and de-authorization: iTunes Store- Authorize or deauthorize your Mac or PC.