Drop off at a Nespresso Boutique or return to your delivery person*. They also supply special bags for recycling - these bags are not necessary to recycle but are very sturdy zip-lock bags which contain smells well. 

Nespresso's website provides detailed, transparent information about how this programme works locally.

For more information see here.

*Some locations also have Nespresso Pod Bins for recycling but Nespresso does not list those locations on its website so you just have to keep your eyes open!