To make the career replacements I used the very user-friendly tool Stubble, found here:
With the help of this tool, you can change almost any text string in game. It has a search function, so you can search for example for "Science" and find all text strings with it. It does take some time to do this, as the careers for example is not only just the titles, but also a lot of other stuff, and I am still tweaking my career replacement file and will update it eventually.
I had good help from the files that Twallan created for his
Career Mod. As I wanted his additional careers also, I used it as a base. I haven't attempted to make all new careers yet, just the replacements. Mainly because I needed to have them more, and also to see what is missing now when the basic ones are replaced. However, Twallan also made a tutorial how to do this, it's found here:
That is next step, but I think I will wait and try until after the hurricane, AKA the first expansion World Adventures, hits my game.