Open the Document Manager using the icon on the "Numbering, drawing" toolbar (or using "Document manager" on the Advance Steel menu).
Select the drawings to convert to PDF files and then click "Add to batch plot".
The drawings are (temporarily) copied to a branch called "Batch plot". Right click "Batch plot" and select "Choose a plotter".
Select the "DWG To PDF.pc3" option (as shown in the figure below) and click the next three OK buttons.
Your drawings are converted to PDF files and they are in the "Work" folder.
This option is only available for users who have AutoCAD® 2007 or 2008.