If it were me I would cut the ribbon out of fondant then use scissors to get the slits.
is it a fondant ribbon border that is hanging low with slits cut into it?
It certainly looks like that. I would use a pizza or pasta cutter http://www.dchefonline.com/products-dchef3 and a self-healing mat with guides http://www.dickblick.com/zz589/00/, because you need even spaces between the cuts and it will take you forever to measure all this cuts. I'd say you have to work fast, and finish one tier (or even one side) first and then the other. Don't cut too much into your ribbon or it will be breaking constantly. Good luck and let us know how you did it.
Yup, looks easy to me, snip snip snip!
Thanks for your help and suggestions!!!
yep, definitely use the scissors I did a border like that before on a hawaiaan themed cake and snipped with scissors for a fondant "grass skirt" look. just make sure when you attach it to only put water or edible glue on the top edge of the fondant and don't put too much water or it'll drip down and the bottom "fringe" will try to stick to the cake too and you'll lose the effect.