Hi Chuckiewokie,
To reset your game files head to steam and verify the integrity of the install (right click the game -> Properties -> local files). This will replace any vanilla game file.
If you're on the latest Alpha then DMT isn't needed as they've built in harmony support now. You'll need an A20 compatible version of the mod and just drop it in the mods folder. DMT is only for people wanting to run mods on the older alphas now.
Cheers,
Hal