Wiping laptop hard drives for disposal. Should I wipe the drives with software or remove the drives and physically destroy them?

Hi there,

I'm moving out of state and have 3 old laptops I don't want to bring with me. Problem is, there still information on the hard drives, some of which contain sensitive information like social security numbers. I'd like to ensure that no information can be recovered from the drive.

Would it be safer to use software to wipe the drives? Or will it be just as safe to open up the laptops, remove the hard drives, and smash them with a hammer?

Thanks so much!