First create a gold Dante trial in the editor. You will need multiple rounds to reach gold; you can see the current medal difficulty of your trial on the right side of the main editor screen.
Then upload it to the EA server. The achievement should unlock immediately.
The quality of the trial doesn't matter, but as a common courtesy please delete your trial from the EA server after you upload it (and get the 'chievo) if it is untested and/or otherwise junk.