So, I have Reach on an Xbox One, and there is no Waypoint app, only Halo Channel. Is it possible to use my computer and get it wirelessly, or is there a way to use Halo Channel?
This is discussed in detail in the sticky thread (How To Get The Halo Waypoint Armors For Halo Reach) on this forum but the general understanding is that the armor pieces can be unlocked only on the Xbox 360’s Halo Waypoint app with a Gold account. After they’re unlocked, you can then import them into the Xbox One. I don’t have a Gold account so I don’t know what the current situation is but I unlocked my last piece of Waypoint armor during the free play weekend in May 2018 and everything was still working correctly then.
The only way to unlock the armour is using the Halo Waypoint app for the Xbox 360. If you don’t have access to that then I’m afraid you won’t be able to unlock anything. For detailed info about how to unlock them, please see the pinned thread as noted above.