I have a rope secured to the bow, get on top of the roof of the camper and pull the kayak up. I have three Yakima bars mounted on the roof. Two of them hold the kayak, the third is mounted at the very rear. The third bar serves as a pivot point and is a great place to secure my feet from and slipping. Third bar is also a great hand-hold for getting on and off the roof from the ladder.
But if I'm just going to the local lake I hook up the trailer and put the kayaks on it instead.
2005 Dodge Ram 2500 CTD,4X4,NV5600
2014 Adventurer 86FB