Lumina,
If that is all you are taking, one 7.5 a day, you shouldn't have much trouble getting off them. I would take the advice above, cut the half in half and try skipping a day in between dosing. Please stop now if you possibly can, because it gets WAY WORSE !
Oxycodone withdrawal is terrible for people like me who take 120-180 mil. per day. Good luck and stick with your plan, you'll be glad you did, you don't want to end up like me[xx(].
Jonesing