"I will act differently."
Translation:Ich werde anders handeln.
Machen can mean either to make or to do. In your translation, it's probably to do. However, there's a very subtle difference between to do and to act, at least in my opinion. The difference, in my perspective, is that to do refers to the actual performance of an action, whereas to act refers the general style of doing, as opposed to specific instances. Thus, machen would also differ slightly from handeln.
If anyone else has a different (maybe even better) understanding, please feel free to say so. :)