I need padding in these seats?

Why not get some extra foam, put it on top of what you have and wrap some fabric around it, using sticky velcro on the bottom to hold the fabric on. You can make a large pillow case in a fabric of your choice and use fusible web to hold it together. Slide it over the pillow and tuck the remainder under the seat.

The shape and design of these cushions, and the shapes of the pattern pieces used to cut the fabric were designed around a solid firm single piece of foam. It would seem that yours have gone flat simply due to age. Trying to firm them up by stuffing in pillow stuffing will be ineffective, as the little pieces will just shift and bunch up, making the cushion very bumpy and uncomfortable to sit on. Pillow stuffing is a less dense foam that what you have now with the solid piece. It was not intended to be used for sitting furniture. To support the weight of bodies sitting on the seats, the foam inside the cushions needs to be both the right thickness and density.

To access the inside of the cushion cover DO NOT cut the back. Doing so will lose any integrity that the cushion has left, will cause raw frayed edges of fabric, and will destroy what seam allowances there may be. To open the back seam, use a seam ripper instead. This is the correct tool to 'cut out' any existing stitches. If you hope to reuse the same covers, you will need the seam allowance fabric to tuck in, and to adequately sew back up again.

Solid dense foam pieces can be pricey. Do you have access to a Joannes or Fabricland retail store? If so, check with them to see when they might be having their next sale on foam slabs. The longer pieces can be cut into smaller pieces the size of your individual cushions with an electric bread knife.

Flipturn, Thank you for that awesome help you are a life saver. I will check the local store to find out if they have the foam. I would not want to ruin the set I have here. This was bought this month so I was wondering why the seating was so flat. I will do what I can to follow your advice. I thank you once again.

Did you buy this a MONTH ago? Take it back. Get something at Home Depot or Lowes in the outdoor living section. They all have some great seating.