I had the same problem last night.After you regester your product you need to go to my essentals login there and you will find what your looking for.Sorry I can't give you more help at this time .I was tired and had a upset wife complaining all through the setup.I will try to back step and see if I can give you better info.
My setup for Pandora worked the 1st try. I went to internet.sony.tv and logged in to Essentials. From the login, I selected the tab 'Personalized Services', and then selected the Pandora 'link to service' option. On the BDP, I went to setup Audio, and selected Pandora, and there got the code I had to type in at internet.sony.tv. Maybe I was just lucky, but its been streaming Pandora for a day now and haven't heard an Ad yet!
ok so i found the broken link as well and followed the instructions to go to Essentials and login there, thats where I'm stuck because in order to login you must give a registration code from my Sony Player but when i go to the page on the player that I was instructed to, all it says is "Device already registered" no code. Now what?
Call Sony support and ask to be escalated to Level 2 support for a registration code reset. You will need the MAC address found under System Settings for the player. The tech stayed on the line to confirm it reset, took him less than five minutes - there are similar posts on Amazon for this issue.