How to hibernate a northern leopard frog

[Crystal6]

I've heard you can induce hibernation in leopard frogs by lowering the temperature, but how do you do this? Is it a gradual process?

I think I read somewhere you can put them in a fridge....? Does anyone have any information or suggestions on how to go about this? (Links to other articles are also welcome. I tried google searches but no luck.)

Thanks in advance