If you're referring to the administrative password for a specific Windows Azure SQL Database server, you can do this from the new portal. Select the Database choice on the left, then select Servers:
Then, after selecting the server of choice, you'll see the option on the right for resetting admin password:
To reset the administrator password for a SQL Database server, use the following steps:
Go to the Windows Azure Management Portal at http://manage.windowsazure.com and click SQL Databases in the left-hand navigation pane.
Click the Servers tab at the top of the SQL Databases workspace. This will launch the Server List View.
In the Server List View, click the name of the server to update. This will launch the Server Dashboard.
On the Server Dashboard, click Reset Administrator Password under quick glance tasks on the right-hand side of the workspace.
On the Reset Password dialogue, specify a new password and then confirm the new password.
To complete the operation, click the Check mark button at bottom right. You will be returned to the Server Dashboard for the server.
If you reset the SQL Database server password during a time when there are active connections to databases on the server, you may want to use the KILL statement to terminate user sessions. This will force client connections to refresh their sessions with the database and the host server. For more information, see KILL (Windows Azure SQL Database).
Another variation on new Azure portal (bypassing the database), #1 go to SQL servers directly; #2 click on the DB Server you want to update the password for, #3 click the pencil, #4 update the password, confirm and save.