torch is your best bet usually...you can also force a socket that is smaller than the actual diameter onto it (hammer and persuasion)...try to use a socket that is 6 sided not 12 sided and then use lots of rust penetrating lube then get a really good breaker bar and then a really long pole for leverage, but in the end you'll probably still need a bit of heat from a torch to just break up a little of that rust and it'll get you started.