How did you kill the Dungeon Guardian? And what were the most frustrating parts of it?

I had no problem luring him out, the problem was that I made my skybridge a little too close to a floating island...I had him down to about 25% health, and then I hit the island. Less than 2 minutes later, I had over 500 cloud blocks and walls. After 20 minutes of minigunning the DG with chlorophyte bullets, I got my bone key :)