You can also open the apps “Get Info” or “Show Inspector” inspector window from the right-click menu, and drag the icon files to the apps icon in the inspector window, and it changes to the new one. But it has the upside that when you want the original you simply can open the same inspector select the icon in it and press delete, and the icon will change back to the original. By the way, I like the icons you made, did you think about a green one? Just because the original has a bunch of green in it.
That was how I was doing it at first, but I found that it wasn’t taking at all sizes. Once the icon got down below 64x64, it was fuzzy as all get out. So I overwrote the actual ICNS file and had much better results. The info panel trick is great for quick testing, but I’m not sure it’s the best choice for the final placement.
I did try green. I tried every color. But I made it at 6 this morning and figured I should probably trim down the options before my whole Saturday morning got away from me :).
I understand, I didn’t know that.