Open the image you want to keep, save the image as a 256 color one. Then, go to file > save AS.
Save as saves a different, new file, while save overwrites a previous saves or saves a new file.
I think it's time for a smiley makeover. I think we're missing some faces. Maybe we can have a snazzy contest to see who can make the best smilies. We can hace faces already decided, and people just have to make them.
How about it?