Bending exhaust headers

Hey I have an exhaust header I need to bend to fit. It’s a v6 header so there’s three tubes. How do I bend without kinking. I’ve been looking and have found filling with sand and bending keeps it from kinking. I might try that. However my shop teacher had the idea of heating all three. Then cooling one and maybe it will bend it the other two when the cooled one shrinks. Could that work. It doesn’t need to be bent more than a half inch.
Any help will be appreciated. Here’s a pic of it. The bottom sharpie mark is where it needs bent. The top is where it is hitting.

 

If the header is hitting in only that one spot, use a ball peen hammer and dent the tube just enough to clear. It's done all the time and no, it won't appreciably affect flow. It will be a lot easier than trying to bend the whole thing and be less destructive than heating all the tubes hot enough to bend them.

 

Just kidding, what he said ^^^