One of the most frequently asked questions that I get when a new root method like towelroot comes out is "How do i return to stock for warranty purposes?". Most of the time if all you need to do is unroot your device you can just boot into recovery and wipe data, if that doesn't get you unrooted there is also an option to fully unroot in the SuperSU app. If you have changed any of your system apps, you will want to not only unroot, but you will also want to flash a stock image in Odin. This will also get rid of any custom recovery if you have one installed. The Galaxy S5 on Verizon now has some stock files for Odin flashing available for download. It is super easy to get back to stock this way. You can head to the link below for the downloads and full install instructions.
Via XDA