This achievement is for uploading a single file (Screenshot, Film/Clip, Map variant or Game type) It doesnt have to be your own, you can just go to the Menu (Press
on any screen) go to File Browser, Most Downloaded, Screenshot, Open the top one, press
and click download.
Then from the File Browser menu go to Local Files, Screenshot, press
and Upload to File Share. You dont even need to play the game, though im sure everyone bought it for that purpose, so just skip the first process.
Thanks to Curtieson for this suggestion:
To speed up your achievement gaining hit Recommend to friends
on the file you just uploaded to unlock another achievement.
Here's a video to demonstrate.