Advance Steel ribbons can be activated together with the AutoCAD ones. This option is available starting with AutoCAD 2009, and the ribbons automatically appear when you switch the workspace to : 2D Drafting & Add notation or 3D Modelling (see the attached picture for the location of the workspace switch option).
Advance Steel 2010 has also Tool Pallets which together with the ribbons provide full access to all AS commands. To enable the tool pallets, you need to go to the Autocad "View" menu, and choose : Tool Pallets. This will activate all the tool pallets (including the AutoCAD ones). In order to isolate only the Advance Steel ones, you need to right click on the tool pallets window and choose : Advance Steel.