You just need to right memory address. You can then just hardcode a pointer to that address, and use it to overwrite the value. It's not hard to code, only like a line or two, but you need the right address. Also, you should find your way to the right memory location from somewhere fixed in memory. If it's loaded from a file, you'll likely need to use an indirect access, possibly through a few pointers.
The harder part is finding the memory address, or how to obtain the right memory address. I don't recommend a simple memory scan since you won't know if it's in a fixed location or not. If you want to be sure, you kinda need to take a look at the assembly to see how the memory is accessed.
In short, I don't quite have the answer you seek, but I think Hacker was looking into how to find that memory address. Once that's found out, the code should be easy.