Couple of questions

[Silverthorn]

how can i add this code? which programs do i need?

The screenshot A-Man posted is from OllyDbg. That's the minimum you'll need for it allows you to change assembler-instructions and, albeit not fully intuitive, save those changes into the exe. @Lord Silva once made a debugging tutorial using Olly which might be of interest to you:



Alternatively, use the DLL Framework so that you don't have to change the exe every time to make one minimal edit.