I know a lot of people ask without searching before, but I did my research before. If I had found a video of the achievement being done, I would be studying it by now, not despairly trying to found the solution on this forum. A lot of people said "it is doable alone" but what they said doesn't works for me (lot of "missed" and "out of sight"). And I did not found a video showing the successful achievement. So I guess there's only one solution left, find 4 other people willing to lose their time for that.