Just create a new character and save the file. Then rename it to combat, stealth or diplomatic and put it in fallout2/data/premade/. The bio files for the original premade characters are in this folder too. If you don't have this folder, create it or extract it from master.dat file.
The images are in fallout2/data/art/intrface and names with combat, stealth and diplomatic aswell. You need the FRM animator to edit the graphics.