Steering sticks in both directions

My grand daughter called me when the car would not steer. I thought she maybe broke a belt or it loosened up and just lost power steering. Being night time and close to home, I switched cars and drove hers home. The steering did not lose power, it stuck at points in a turn. Stuck hard and I had to yank hard on the wheel to get it to release in either direction.
I made it home, and the next day, jacked it up and removed the drivers front wheel because I spotted a torn boot. I thought there was the problem. I removed the tire, opened the drivers door, sat part way in and turned it on to watch the wheel while turned it. The first thing I noticed was it did not stick. The next thing I noticed was the car had fallen off the jack and onto my foot. I knew I should have used jack stands but with age comes insanity and I am getting old. Anyway, I now have a clearly broken tie rod, but should I replace the rack and pinion as the previous owner did say she was told it might have problems. I have a nice friend who has another buddy that is a shade tree that is recommended to me who offered to change the ball joint which he thought might be the problem, before he can see the car, but he also came to the rack and pinion conclusion and wants to research it a bit before he replaces it. He is forty years younger than me, and now I of course have crutches and two broken bones at the ankle so I cannot crawl under and have a peek even with the jack stands.
Are they difficult to replace? The directions I have read make it sound simple, but I am leary. Can a guy of seventy in crutches pull it off, or should I let the kid try?