Cleaning oil out of radiator

[Poorboy04]

I purchased a new motor for my tc35 and I want to clean oil out of my radiator (before I install it on my new engine). I have also purchased new hoses. So the only thing I need to clean is the radiator itself. The radiator is off and on the shop floor. What is everyones opinion on how to clean the radiator.

 

[Looking4new]

Hot water. Lots of it.

 

[Chewwy]

SOAPY hot water, followed by multiple rinses.