How do I get rid of a snake in my garage?

That is one serious snake and if you don't want to use the mongoose then I suggest you put some mothballs throughout the garage because snakes can't stand the smell of them and it should drive it out. A friend of mine had a snake in his van and moth balls drove it out. It will give your garage a strong smell but that's better than getting bit by a rattler. A black snake would work too but who wants to mess with that? Good luck!