right-click on pic>>>>>edit.....this will open pic in microsoft paint

on the top row select "image">>>>>attributes......this will tell you it's size

on the top row select "image">>>>stretch & skew....this will allow you to make it smaller in a percentage of it's current size

example: a pic that in "attributes" shows to be 1024W x 768H, if you "strech/skew" it 50% will then be 512w x 384h

you just keep "stretch/skew"ing it till you get it under the requirements.

btw: if you stretch/skew it by diff % on h/w, you'll distort the pic

hope that helps