I think this should work...
private void yourMethodName(final String newLabelText) {
one.setText(newLabelText);
}
if you want to use this method universal...
private void yourMethodName(final JLabel label, final String newLabelText) {
label.setText(newLabelText);
}
now you just need call this method(s) with the parameter(s) you want to change. If the changes are not diesplayed, you need to repaint the container where your stuff is in. If you don't use a container I would advice you to create one and add all your stuff into this container. The aswer of this thread might be helpful.