The radiator on your Opel Corsa is located towards the front of the vehicle and can get damaged from rocks or other debris on the road thrown up by other cars and directed towards the radiator. The radiator is made of very thin pieces of aluminium, which are excellent in terms of heat dissipation and cooling, but can easily get damaged. If your radiator has been punctured or is leaking, replace it right away so that the problem doesn't get worse. If you don't replace the radiator, you could lose all the coolant from the motor and cause it to overheat; it is much more economical to replace the radiator than the engine.
Allow the engine to cool down before removing the radiator to prevent burns.
Place a drain pan beneath the radiator.
Loosen the drain bolt at the bottom of the radiator and allow the coolant to drip into the drain pan.
Loosen the upper and lower radiator hose clamps with a flat head screwdriver and pull the hoses out of the radiator.
Unplug the connectors for the radiator fans by pressing down on the connector tab and pulling them out.
Remove the two fans from the radiator by loosening the four bolts at each corner of the fans with a ratchet.
Remove the radiator by loosening the four bolts at each corner with a ratchet.
If the radiator hoses don't come out easily, try twisting them left and right then pull them out.
Wear safety glasses, when working on your Corsa, to protect your eyes from injury.