If you want to change the appearance of your link boxes on a global scale in Acrobat 6.0 you can easily accomplish this in three steps:
- Display your pages in Continuous Page Mode (View>Page Layout>Continuous)
- Select the Link Tool
- Select All Links (Ctrl+A / Edit>Select All)
- Display the Properties Bar (Ctrl + E / View>Toolbars>Properties Bar)
Any changes you make to the properties are applied to all of the selected links.