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Just unbolting the hump leaves the plastic mounting point of the seat pan still sticking up through the fabric. It is very easy to just trim this section of the seat pan away with a rotary cutting tool.
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You can see that you will have to patch the two round holes in the cover and add some foam before sliding in some plastic from a milk jug above the opening to form the new seat pan.
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I got a scrap of carpet pad free from the carpet store and bought a small piece of seat fabric and some vinyl adhesive from the fabric store.
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Cut 4 circles of fabric by tracing around an old cap from a coolant jug. Sandwich them together, inside and out to repair the holes. After that dries you can add another bead of adhesive around the outside to seal the edges down. This has been a really good repair and shows no sign of coming loose after a year of riding and 8,000 miles.
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Trial fit a couple stacks of the 1/2 inch carpet pad and temporarily slide in the plastic you cut from the jug on top of the opening in the pan to adjust for an even feel to the foam when sitting on the seat. I only ended up using two layers even though it looks like you would need more to bring it up even. You can build in a nice pocket to suit and removing the hump gains 3-4 inches of legroom. Once you are happy with the foam you can hot glue the pieces of flat plastic across the inside opening of the pan to support it.
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This is a very cost effective mod and highly recommended.