blue hose? Never saw that before. If there is a little bit of stub still left on the radiator, pull the plastic piece out of the hose and just re-clamp on. I'd keep a constant eye on the temp gauge and watch for leaks as such a fix is very temporary. Then, you will likely need a new radiator. These can be recycled and have the top piece replaced but you will pay nearly what a new aftermarket one costs, just to have that one fixed.