This is basically an achievement that you do by rebuilding a part with someone else, if, for example, you are pinned down to the ground and you lose your balloon constantly, you sit on the balloon along with another person and you rebuild it all the time. Other common situation where you do it is when you lose hull quickly all the time, taking alot of enemy fire, and where another person from the ships helps you in keeping the ship alive. I didn't actually farm this particular achievement, for more often than not I found myself in a situation where two of us just had to be glued to a component if we wanted to repair it fast enough to survive another day. I suggest doing it on a goldfish or squid, as you find yourself in such situation alot and usually there's two people keeping watch of the hull on those ships. Other ships, such as galleon and pyramidion, are ok too if you fight against someone that intensely puts your hull down, but you don't have any enemy in a gun arc. It is doable in normal play quite easily, and doesn't really require farming (at least not as much as 1km kills).
