I would teach him to 'target' things in general. Since I began clicker training and shaping, Jackson usually offers all sorts of behaviors with any new object I sit in front of him. He'll try to paw at it, kick it, touch it with his nose, etc, until I give him that click and he figures out what I want him to do.
So you can take ANY object... like a CD case or DVD case, etc, and hold it out to him and wait for him to paw at it and when he does, say 'yes!' or click or whatever you do and give him a treat. Once he gets the hang of that, move to the soccer ball. Put the ball in front of him and kind of encourage him to kick at it with his paw... sometimes I 'show' Jackson what I want him to do... I don't know if it really works but it seems to! So push it around with your own hand a little bit...and just keep waiting. The minute his paw touches the ball (even if the ball doesn't move) treat him! Don't use any verbal cue until he's doing it over and over again, and then you can add the word 'kick' or whatever.
