Thanks Jason, that gave me enough info to make the change. I looked through all 35 pages of this thread and didn't find info on how to add the images. so here's a quick tutorial for others.
Start with the same process of letting the game boot all the way to the attract screen, then press the windows button.
Navigate to the c: drive
Then PGA_Tour_2006 folder
Then Shell
Then Images
Then GolferSelect
Within the GolferSelect folder you will see four images for each of the golfers on the select screen. Find the golfer that you replaced, ie: Tiffany Williamson was replaced in my game with Tiger Woods. Drop the new Tiger Woods images into the folder. You need to copy the file name from the replaced golfer (Tiffany Williamson), delete that file, then paste the copied name into the name of the new file (Tiger Woods). Do this for each of the files. Gist of it is, old files names need to be used with the new files.
Thanks Spitfire for the images. I'm tempted to replaced all of my images now.