Your OS likely has an image editor (such as MS Paint if you use Windows) that you can use for simple image editing. There are many free image editors you can download for more sophisticated image editing.
No matter what, it will be far easier to create a suitable image in 16x16 than to get around that restriction. Even if that was possible, all icons would be 16x16, with those two being larger. That would even worse than the current state of affairs, in my opinion.
No matter what, it will be far easier to create a suitable image in 16x16 than to get around that restriction. Even if that was possible, all icons would be 16x16, with those two being larger. That would even worse than the current state of affairs, in my opinion.