Mmmmm, pepitas. ^ Try this:

Clean all the slime and strings off them, rinse them, then lay them out on paper in a single layer to dry.

Once dried, use a rolling pin to crack the hulls. Then dump them into a bowl of water and stir vigorously to separate seeds from hulls. Hulls will float, seeds will sink.

Put the seeds in a frying pan and heat on low. When the seeds start popping or cracking, stir them while heating for about 3 minutes. Salt. Enjoy.