Required Tools:

• charles
• firefox

1. Open Charles
2. Enter CityVille [ play now ]
3. Go to Charles first and find the line "http://fb-client-0.cityville.zynga.com"
4. Expand it and you will see 'flashservices/'
5. Expand and you will see a lot of gateway.php(FlashService...)
6. Right click any of the gateway.php and select "Breakpoints"
7. Now, reload CityVille.
8. A Breakpoint tab will appear in Charles.
9. Press EXECUTE once. 
10. Another breakpoint will appear with an Edit Request tab
11. Click on EDIT REQUEST > AMF
12. Expand everything till you can see your own profile with the number of coins and cash that you have. 
13. Change the cash value to 100
14. Go back to your session tab and remove the breakpoint.
15. Go back to the breakpoint tab and Click Execute 
16. The game will now load and you should see your new cash. Spend them on the community buildings now as they will disappear