I am not sure what you mean that the icons are not fitting correctly they are the correct size. How are you trying to import or replace the image? Are you trying to replace a single one button icon (one one side of the remote i.e. the left or right side) or a wider icon that spans across both buttons?

If you need software for resizing buttons, icons, or graphics try...

[Link: guifx.com]

Or something a little more advanced try...

http://www.gimp.org/

Thanks,
Matt