Not sure it can be done without console commands. I used Dotame on one; that works, so it may be possible, but watch out for the Atal-Arak on its back. I'm not really sure what that thing is, they seem to work as a unit before taming, but after taming the Arak attacks its former host. I couldn't find a way to kill it until after the main dino was dead.

so you have to tame the atal arka, and then craft the drago in the arkas inventory, and then consume the item in your own inventory. it takes 1000 "element thread" that the arka creates over time, plus other materials.