first, it looks like your gooseneck plates are splayed out? Pull them back together so you can put a pin thru the holes.
Then tie your cunningham line to one of the unused holes, lead it up thru the sail cringle, then back down other side a short ways. Tie a small block to it, a few inches above where you are going to put a clam-cleat into the mast. Then tie a line from one of the gooseneck holes, up through the block and down through this cleat. Now you have a 4 to 1 advantage.