Note: I'm using V19 I'm not sure what I'm missing here. I haven't used EPC for a while and am trying to set my line thickness to 8 thou. I can change it line by line using the properties dialog, but I expected that changing the thickness in the technology settings would change all existing lines that use that style. This image hopefully shows what I mean: http://www.mike-warren.net/tmp/EPC-LineStyles.jpg Even though I've changed the width of style 'Normal' to 8 thou in the technology settings the lines are still 5 thou.
Go to Settings > Design Technology and you'll find a "Connections Tab about ⅔ of the way along the dialogue box – this is the tab where you adjust the style/thickness of schematic lines!
If you want to change the style/thickness of component outlines/graphics in the Library Schematic and PCB Symbol Editors, you DO adjust these from Settings > Design Technology > Line Styles!