Help me/stupid question on MAC computers

So I'm trying to get this gif resized and I figured out to get it 500 x 100 for the signature however its still over 1MB+ and it has to be less than 15kbs which is super small. Is it possible to reduce size of this gif without making it blurry/ un-viewable. I am on a MAC computer so not every program works. Whenever I try to reduce size it either is still too large or just goes to a blurry and confusing gif. This is the gif im talking about in question. Thanks http://gph.is/1VYLZy6

 

Google search and download Photoshop CS2. Adobe is giving away that download for free. Save image as a "Image for the web" and fiddle with the controls until you get it to the dimensions and file size required.

The trick is to simplify the color palette. 256 colors makes the image super smooth, but also large. 128 is small and not so choppy.