They're called spring clamps. They're used everywhere because they're wicked easy to install on the assembly line. But they're a pain to remove. There are special tools made to do it, but they're cheap.
The tools are called a spring claim tool or hose clamp pliers. Only about $10 - $15.
Any parts store (Autozone, NAPA, O'Reilly's) should have them. Also Harbor Freight or Amazon.
BUYt now you'll have them for al the outh hose clamps you need to replace. I replaced the spring clamps with stainless steel standard hose clamps..the kind you screw tight.
Be careful on the radiator fittings. They're plastic. I've got a 2012 1.4L Turbo. Top coolant hose from engine water outlet to radiator is pre-formed, GM part #95129353. Best off EBay. Costs about $16. Good luck.