[Scripting] Unequip item

I'm playing around a bit with ai scripts for characters, since I haven't tried it for well over ten years. I'm stuck trying to find a way for a character to unequip items on certain conditions but I'm not finding a good, reliable way to get it to work. Is it even possible at all or is there any workaround?

I managed to equip with 'FillSlot(I:Slot*SLOTS)' (even if unreliable) but whatever I try I can't manage to get them to take of an item.