How to break a 40dpf master lock?

Hi, I have an old harley chained up at my place to keep it safe and of course I used the best lock, a 40dpf pin tumbler master lock padlock. So heres the problem, someone tried to break it by drilling out the keyhole, well anyone who owns one knows these locks are virtually indestructable. Now I can't open the lock, I bought a new lock but I can't replace it unless I get the old one off. I tried using my metal saw but it just dulled the blade. We've been getting alot of rain lately and I want to put my bike in so it doesn't rust. Can anyone help, anyway to cut or break it? Thanks