Is there and easy way to install a doggie door by a 72 yr old female?

https://www.wikihow.com/Install-a-Pet-Door-or-Dog-Door

I'm 71 and I do repairs for my disabled clients all the time, but a handyman works too. Here is a general one for a cat, but you'll get the idea. https://www.youtube.com/watch?v=rOM1M7oMZqU

If you don't have a dremel, but have a drill and jig saw.... you could drill holes with a metal bit in the four corners big enough to fit your jig saw with a metal blade in it. https://www.youtube.com/watch?v=J_bRr7ZAHPM

My preference is for the magnetic pet doors that only open for your dog, and prevents racoons, other dogs/cat from entering.

I recommend you take a look at Home Advisor.com They have all kinds of pros that do all kinds of work. It sounds like you need a carpenter. We have used their pros a couple times and was very happy with results. Home Advisor does background checks on all their pros. So you can feel comfortable having a carpenter in your home. Home Advisor also provides customer reviews, so you can see what other people thought of the pros they used. And, here's the best part, this service is free. I hope you find this info helpful. Best wishes.

If you have a sliding glass door to the outside any place in your house, you can purchase a section that goes inside the slider, and has a doggy door already there. You may also be able to get a screen for the outside of the metal door that has a doggie door, and then just open the inside metal door and the dog can come in. Good luck. Check out Google for "Doggy doors."