buy a new one before you take the old one off as the car will not be drivable
It is often possible to do it by taking the bottom sump plate off (catch the oil). then you can work on it in more comfort on the bench, and can apply heat without fear of setting the car alight. You can also marvel at the sludge, odd nuts and other debris that has collected in the sump over the years, and wonder where the bits came from.