K stands for kilobytes. For example if you right click on your picture and select properties you'll see where it says the size of the file. It's gonna be pretty hard to get a PGN file down to 60k unless you resize it, basically you would need to make yours more then half the size(not file size but dimension size) . Your best bet is to redo the file and save it as a jpeg, you won't have the same effect but it would be in the guidelines.