(Using Hex Workshop) - Open the file 'User.log", or "user1.log", or whichever is your game, and go to DECIMAL byte 7792.
Then in the lower left corner, is a window with several numbers in it (64-bit signed, 8-bit short, etc.) The 32-bit unsigned is the one you are interested in. It should say 5000 because that is the amount of money you start with.
Click this line and you can change it to anything up to $999,999,999. If you put in a billion you win the game and it automatically starts you over at $5000.
Money Exploit
Go to any slot machine, say $1 slot machine. Put all your credits in. Now go to any $1000 slot machine without cashing out. You will end up with HEAPS of money. The trick is to leave the credits in and go to a slot machine with a higher credit cost. If you go to a slot machine of lower value you will lose money.