You can do this via
SimPE and Bidou's Career Editor. You will, though, want the "modifiable" career packages from this thread:
https://modthesims.info/showthread....ighlight=career
Once you have the file(s) you want, extract them to somewhere other than your game folder (I keep a Work folder for this sort of thing), open with SimPE, select "Bidou's Career Editor", make the changes you want, and then save the
changed file to somewhere in your Downloads folder (recommended: a subfolder called "Default Replacements" or "Careers" so you can find them easily if you need to).
The replacement file will override the original with the salary amounts you prefer.
Note: The same procedure can be used to change job titles and, to a limited extent, career outfits (it's possible to do a more thorough job but it's a great deal more complicated).