Use a text editor such as notepad to edit the "RushEngine.ini" file in the "\My Games\The Last Remnant\RushGame\Config" directory. Find the "bExSettingUseAllMemberEquip=FALSE" line and change its value to "TRUE". You can now change NPC weapons and accessories manually. However, they will still ask for new equipment and items. If you give them new equipment they may still override the slot without putting it back into the inventory as usual. Try giving the NPCs the items they want, but do not give them weapons or accessories that they ask for. Do it manually so that you can keep that equipment for selling or disassembling.