You can use a beetle to get them there but you do NOT get a skull just for turning them in. After turning in the skulls it will summon a monster you have to kill, it's not that easy to kill but a very very good tame can solo it. I personally take my Girlfriend along on her Mage/bard just as an issurance measure . It's best just to kill the things in doom and turn them in as you get them, getting 1,000 is relatively quick. If I stay there and hunt I can normally pull no less then 3-4 skulls per hour with my GF there to help me.