Is there a way to change martial arts . . .

[D. Flame]

Is there a way to change the one of the martial arts that came on a weapon without having to farm a new one?

[me mushroom man]

Not that I know of, unfortunately. Slightly shocking considering the freedom to change item affixes outside of charms.

[thorin.hannahs]

Nope. Your best bet is to just pick the weapon you like with the officer's martial art you like and farm that until you get your preferred secondary.

For example I have Hua Xiong's staff but need to find it with the Pogo martial art Ape something or other.

[Vaati]

Unfortunately nope, cant swap between martial arts in current version.

[Lucifer_]

nope. big oversight imo

[Master]

Found a sun quan set sword. Its other skill is a lesser version of the sword's unique skill... sad