Xiǎng / ràng / tā / gǎi / biàn / zhǔ / yì / ？ / Miǎn / tán / ， / tā / yǐ / jīng / jué / dìng / le / 。

想让他改变主意？免谈，他已经决定了。

Want to change his mind? Forget it; he has already made his decision.