We have them all over here and we call them coyote squash. Nice to know they have edible seeds, we have a few growing in town and when they start showing ripe fruit I'm going to go cruise the bar-ditches (that's what they call the roadside ditches here) and harvest a bunch. Anything for food forest and foraging. Tyler, roast them just like pumpkin seeds?
You want to try to get as much of the pulp off as possible because it is extremely bitter. If you roast them until the remaining pulp crisps you can dust it off pretty easily. I just eat shells and all, as the seeds are smaller than pumpkin seeds.
I used to raise competition pumpkins. You are talking to the QUEEN of desliming seeds. As for how, practice, experience, a colander and one of those plastic nubbly chore-girl dish scrubbers or better yet, a brand new bodywash pouf. Scrub gently but firmly all over until you can't feel any more slime, rinse a few times as you go, and have a second colander to catch finished product. There is nothing like cutting holes to stick your arm up to the shoulder to extract the guts from a thousand pound plus pumpkin then squish your way through garbage bags of guts to get the seeds... (if you aren't using the words 'forklift' and 'harvest' in the same sentence you aren't growin!)