They are replaceable, but there are none available. I'm looking to get an inexpensive used set, broken spokes are fine. So that I can get mine up and running again, and have some spare parts for the set on my wife's bike. If you want to sell them instead, let me know. I'll be happy to give you the $40 you paid, + shipping to get them here to me.

At least assuming these are the old ones that Trek sold. The stickers with the brand/model are orange.

If you find spokes, please let me know!