Doors and Windows - Removing old prehung door for replacement

This might be a dumb question, but I was wondering if anyone would explain to me the best procedure for removing the old door, so that I can replace it with a new prehung door?

Getting read yto do this project int he next day or so. I have removed the interior trim, and was planning on using my recip saw to cut the old nails, and then push the old frame out. Just wondering if there was more to this then I think. Anyone who has done this before, I would like to hear from you.

Thank you
Jeff

Interior or exterior?

It is an exterior door going out to my deck. I am replacing because I want to add a dog door, so my pups can run in and out at will

Check the outside trim. If the outside trim has nails, remove them with a cat's paw or crow's foot. Then proceed with the sawzall as planned. Good luck.