I can't remove the spark plugs on my 61 ford falcon

Good thing you have a cast iron head, then. Use penetrating oil liberally around the plugs and let it set overnight. Rust and corrosion may be holding them pretty tight. Work carefully and wrench them out. You may have to use a cheater bar or breaker bar to start them. When you get them out, clean the plug hole threads as best you can, and use anti-seize lubricant on the threads of the new spark plugs. You will be amazed at how easily they come out the next time.