Amazon recently changed credentials their policy, here are the new instructions:
In your seller central account, at the top right click: Settings > User Permissions > Authorize a developer >
Developer's Name : Beau Crabill
Developer ID : 3532 - 6590 - 8382
Check mark "I understand..." and click Next
Your credentials should then pop up.
Go into the Analyzer Tool, click on My Settings, and input into the *shared credentials.