1. Lurking behind NPC merchants, you can't be found.
2. Attack the businessman from behind, be careful and don't let him die.
Stop attacking when the businessman turns around, and the businessman will "forgive you"
4. Archive, return the title, and then re-read the file to enter the game. At this time, you will find that the store automatically refreshes.
If you need a quick refresh after this refresh, just repeat the fourth step, and you don't need to attack the businessman again.