Start by defining the required delivery rules for one of the banners in the campaign, following the steps and hints outlined above.
Once the rules are in place for that banner (and after making sure they have been saved), you can use the “Actions” button on the top right hand side of the screen to open a menu of additional tools.
Under the heading for “Apply delivery rules to”, you have the option to copy the rules to all the other banners in the same campaign, or you can select one of the other banners in the campaign specifically.
Once you’ve selected the target, click the small round grey button with the arrow in it to execute the selected action.
Keep in mind that any delivery rules already present on the target banner(s) will be overwritten!