This trophy is significantly easier after the 1.1 patch. You can obtain this in a variety of ways. Superior (purple) gear drops rather easily from all mobs. You can also get a guaranteed purple from any dark zone chest that requires DZ rank 30 or above to open.
However the easiest guaranteed way to get this is simply to kill a "boss" mob. The "boss" mobs are yellow elites with a specific name like Animal or Hawkeye and are usually found near a landmark or Dark Zone chest that requires a DZ key. These mobs have a 100% chance to drop a high end (yellow) item. The Dark Zone chests that require a DZ key also have a 100% high end drop rate chance so if you have a key you can simply loot the chest to get one.
Once you have the appropriate piece all you have to do is proceed to an extraction zone and signal for the helicopter. Once the chopper arrives simply place your pack on the line to extract your items. If you can accomplish this without an npc or another player killing you then the trophy will unlock shortly after the chopper flies away.