You may even find that if you can't swap your package you may be better off cancelling what you have already booked, loosing your deposit and booking again with the free dining. Free dining is worth quite a bit for larger families and there is also the $100 gift card to take into account too. You would need to have a look at costs and see if it would be worth it for you though.
For us we would want to upgrade to the regular dining plan (1 table service meal, 1 counter service meal and 1 snack per day plus a refillable mug) as we found the table service meals a lot more relaxing and a good way to take a break. All the character meals are table service credits so again you would need to have a look at the cost for you paying for any table service meals out of pocket versus the cost of buying or upgrading to the table service meal plan.