If you still have the original box, you can use it to return your package. 

Otherwise, a new, sturdy box will also work fine. 

1. Properly pack the device, including all of the accessories and documents that came with the device, into the return packaging.
2. Add cushioning to secure the package.
3. Close it with a piece of tape or adhesive to ensure the box does not open during shipment.

You can also take a photo of your package once ready to return. This can support you in any case where there are potential return shipping issues or damage.