1.Open saved game 
2.Use search button and under search for text type Bane(for example). 
3.And below "Joe Bane" there are similar hex codes for all of the gangsters : 
AFBE ADDE AFBE ADDE AFBE ADDE etc.Well the ADDE adresse's are the experience 
and skills for the specific gangster you chose to edit. 
4.There are only 9 ADDE hexcodes 

1st ADDE= ? 
2nd ADDE= assassin skills 
3rd ADDE= spying 
4th ADDE= robbing 
5th ADDE= charmer 
6th ADDE= bomber 
7th ADDE= safe cracker 
8th ADDE= driving 
9th ADDE= kidnapping 

5 stars = AD7E 
3 stars = AD1E 
2 stars = etc. 

YOU CAN HAVE MORE THAN 4 SKILLS BUT ONLY DRIVING SKILLS AND SAFECRACKING 
The combination of 5 skills can only be used like this 

Basic Skills (2 skills) 

1. Combat 
2. Stealth 

Skills with "interface" order only 2 skills combination allowed e.g 

Additionary skills (2 skills) 
================== 
1. Spying (1.2, 1.3,etc) 
2. Charm (2.1, 2.3 etc) 
3. Bombing (3.1, etc) 
4. Assasin (4.5 ect) 
5. Robbing 

For example if you want an assasin with bombing skills you can just edit the 
appropriate addresse then if you want driving skills as well edit the 
addresse that is for driving.When you go back into the game you will see the 
assasin skill,and the bombing skill.You will not see the driving skill symbol 
but you are able to drive just as good as a 5 star driver!!