How do you complete lao-shin quest in monster hunter freedom?

Answer 1

you must defend the fortress by not allowing Lao Shan Lung to reduce it's integrity to zero.

you can't naturally kill him by yourself unless you're a G or high rank defeating a low rank lao shan lung but when you're on the same level, just try to stagger it alot and time those stagger when it's about to land a blow to the fortress, that way you'll stop it's attacks temporarily until the time runs out.