I know this is a noob question but anybody know how to loosen these clamps? All three hoses are leaking coolant at the T and I need to swap them out.

 

you can get them off by placing a small screw driver blade under the hasp, but they can not be reused. you will need to replace them with screw type

 

Is it possible to stop the leaking just by replacing the clamps or do I need new hoses and T?

 

How many miles are on the vehicle? That hose is sold as a single unit, tee and all. You may be able to get by for a bit by shortening the hoses if the ends are weakened, and re-clamping them onto the tee, but it's generally recommended to replace the entire hose.

When my upper hose began leaking 5 years ago at 110k miles, I replaced every single piece of hose and plastic tubing on mine because I knew they were all the same age.

 

i dont see why you could not replace it with a good stainless screw clamp