How do you add the cron job for cubepoints to work?

I’ve never created a cron job on any site previously, so when cubepoints requested I make one for it to be able to upadte points automatically as users earn them I was stumped. I’ve seen a million or posts about cron jobs but nothing directing how to do so for this plugin. I would really appreciate any help possible with this you guys can provide.

http://wordpress.org/extend/plugins/cubepoints/