I think there was a tutorial of some sort on the build 30 video, which you can find on their home page, I remember seeing them uploading one, have you checked the main menu and everything?

Not the autoplay video on the home page? i'll go look around

First thing first: Did you create the mod yourself and did you get the permission of the author? It would be nice if you would give a credit even if the guy is long gone from modding community, just by mentioning his name in description and that he's the original author.

Apart from that, you just create a mod, launch the game with mod, and then go to Editor submenu and then select the publish thing, and then simply follow the given steps.

Yeah, I figured it out, those are indeed the correct instructions.
Yes, i'm the original author of the UNSC :)

I know this thread is long dead, but I'm trying to upload a mod and it shared successfully but fails to publish everytime?