Take a fire or lightning wyvern, set fire to the packs and then chomp em.. easiest strat. If your too scared to do that? Get a buddy to go with you.. if your still to scarednthen your not ready for this beast.
I was sitting on a flyer on a cliff above the deinos, thought I was safe to wait for my moment to steal their eggs...had the biggest heart attack when one of them decided to climb up the cliff. I accidentally dismounted in shock and fell right into the packs claws, where they shredded me to death. Don't be scared of them, they smell it.