What you'll need:
ISO
Sharp knife, Scissors, or Razer Blade
Something to wipe with
New Oven/Turkey/Volcano/Etc. Bag
Take your stock bag.
Pull hard on the bag, pulling out the bag system. You can see how the outer ring is on backwards. My fault.
Pull off the outer ring. It looks sloppy because I had to disassemble this valve to figure out how to reassemble the other ones.
Pull off this orange ring and put to the side.
I wipe everything down very well with ISO except the orange ring. Be careful not to break the inner valve thing or rip your silicone mouthpiece. If this happens its no big deal.
Take your bag and pinch it/bunch it up evenly in the middle. Make sure the top is somewhat even.
Slip over the orange ring. Make sure all of the bag makes it through the ring.
Blouse or pull over the top of the bag a half inch to an inch over the ring. Make sure the bag is above the ring and evenly dispersed.
Reinsert inner valve piece. Note how even the size of the blouse is. The bottom is even, just a bad pic.
Cut excess bag off. Make the bag flush with the top of the inner valve piece. Be careful not to cut the orange ring. If you do cut the ring then you simply make a new one using a a piece of turkey bag.
Decent cut. Make sure all of your bag is tucked in. Try to position orange ring near top.
Another view.
Slide on outer valve holder.
Enjoy a fresh bag, and put your other freshies back in the box.
If your finished product leaks then take it apart and make sure the bag is completely above the orange ring. I had to take apart the valve in the pics and readjust.
Don't get frustrated if you are having trouble or problems with this method. Remember the bags aren't desgined to be replaceable, or are they?