Kayak repair (installing new 6" center hatch on Scupper Pro)

I have a Scupper Pro that the center screw hatch didn't work on, so I've removed it to install a new hatch. Problem is, the holes for installing the new hatch don't align with the holes from the old hatch. So I'm wondering what the best way to fill/repair the old holes is before drilling the holes for the new hatch.

The best two options seem to be:
1. Buy some HDPE plastic rods and use a heat gun or soldering iron to plastic weld and fill the holes.
2. Buy some poly epoxy (like https://www.tapplastics.com/product/repair_products/plastic_adhesives/tap_poly_weld_adhesive/435) and use this to fill the holes

I have a feeling that #1 is the correct option, but wanted some more experienced opinions on what's the best way to do this.

Call Ocean Kayak and have them send you a free patch kit which include a 4" x 4" patch and welding rod. Plastic weld to fill the screw holes.

I have a Scupper Pro that the center screw hatch didn't work on, so I've removed it to install a new hatch. Problem is, the holes for installing the new hatch don't align with the holes from the old hatch. So I'm wondering what the best way to fill/repair the old holes is before drilling the holes for the new hatch.

The best two options seem to be:
1. Buy some HDPE plastic rods and use a heat gun or soldering iron to plastic weld and fill the holes.
2. Buy some poly epoxy (like https://www.tapplastics.com/product/repair_products/plastic_adhesives/tap_poly_weld_adhesive/435) and use this to fill the holes

I have a feeling that #1 is the correct option, but wanted some more experienced opinions on what's the best way to do this.

Ive done this type of repair to a couple of my boats. I’ve used plastic from parking bollard covers or cutout material from installing rod holders.  It was pretty easy.  Got the plastic welder at harbor freight for $15 I think.  Put some duck tape or cardboard underneath the holes to keep it from sagging or running through the hole. Works best if you warm up the kayak material with heat gun first. 

Or you upgrade to a rectangular hatch for another option

I cut a long sliver from the recycling bin and used it as welding rod. I used a heat gun to Do the welding.

Why not just drill holes in the new hatch, so they align with the holes in the kayak? Or cut a ring out of 1/4" starboard plastic and use it like a backing plate on the inside...

Call Ocean Kayak and have them send you a free patch kit which include a 4" x 4" patch and welding rod. Plastic weld to fill the screw holes.

Thanks, I didn't realize they had a free kit! From all the answers here, it sounds like plastic welding is the way to go.