There will be some difficulties actually going to the multiplayer worldwide boss, because if you are not in a party, the chances are you will have to farm it for a while and hope that you will get the kill at some point. In order to make things easier and have more chances of getting the kill you should team up with players around you, because that will make it easier to get the aggro and thus the boss kill. Another thing you should do is try to challenge the world boss close to your level, or below your level, and not the one above your level because it will be even more difficult to get the kill for that (at least without a party). Fighting the boss will be a very good way to gather several red gears, if you are lucky! So try to do it if you want to gear up!