How to register for a new combined Directv/AT&T account

We are new combined Directv/ATT customers who, like several others on this forum, have spent hours trying to get registered for online access to our account.  First we went on Chat, and were emailed a link that was supposed to explain everything, but it led us to a 404 Oops! msg. (Now that I think of it, this really might explain a lot.) We also wasted an hour talking to AT&T Support but they were unable to help.  Are there any clever users out there who have managed to log on??