As long as you understand what is meant about finding centers of drains. You can change the location of the drain from above most of the time if you are doing the change over a finished ceiling below.
Things you need to watch out for is if your new drain is going to be on a joist (not good) or not. You may want to fur a wall one way or the other to miss the joist. If you have to go through a joist make a hole just slightly larger than your drain pipe so that there is room for expansion contraction. If it's tight it will tic at you until the heat is gone and the pipe comes back to room temp.
The height of the floor on your new shower and type of shower fitting you buy. Base for a base should be close in height, but base for modular you will probably have to raise the drain some. The shower fitting should probably be one with a rubber Ferrel that will slid down around the outside of the pipe and then most likely it will have a thin inner nut that screws in and compresses the rubber around the pipe.
Not knowing what your trade is or what your skill level is the main thing and only you know that.
I have been in new home and repair all my life and even thought I am a plumber I do all my carpentry, hardwood/ceramic tile flooring, drywall, roofing and electric. I don't do carpet.
good luck