This right here:
There are three problems:
1) That hose is too thick to just "pinch off". I could probably get another hose clamp and try to do it that way but I'm not sure if that would work.
2) The second I unhook that black clamped hose from the plastic resevoir, coolant is going to go everywhere.
3) I'm not sure if I can reattach that clamp after I remove it.