Board Thread:New on Terraria Wiki/@comment-25753700-20141124015202/@comment-27919501-20160305190254

I'd just recommend the Fireworks method. Summon the Destroyer, wait for it to fly over the bridge, fight done. (Unless all the fireworks didn't hit the Destroyer or they were not enough. In that case, just fly around and attack with a weapon such as the Gatligator with the strongest bullets you have.)