Converting 3 speed manual to auto question.

[Bjj_junkie]

Hello everyone, I'd like to see if I can get a clearer picture of how to swap out a 3 speed manual transmission to an automatic one. Please excuse my lack of auto mechanics knowledge. I have spoken to people and they say it can be done but I have no idea what's the process and what else I need to get besides the transmission.

I recently bought a 72 stepside with a 250 and a 3 speed. I'm pretty sure I'm sticking with the 250 but the transmission has to be changed since I don't drive stick. What throws me off is the floor shifter that's there now. Does that need to be removed and plugged up and get a steering column with auto shifter or what? Like I said excuse the complete lack of knowledge but I'm new to this and my main guy that's gonna help me on this is out of town for a few months

Thanks for your time