You can't cure it now. You can only remove all the infected leaves and burn them or dispose of them somehow. To avoid leaf curl you must spray your tree in leaf fall or/and before the flower buds swell with a copper based fungicide. I do it twice for extra precaution. You can just leave them on there and they will eventually falloff and new healthy leafs will replace them. To remove them just encourages these new leafs earlier. Good luck.

Bordergard thanks for suggesting a copper based product, does it have a name drough

Just ask for a leaf curl fungicide at your local nursery. Then you should be able to get one. Make sure it's copper based though.