Best way to upgrade Ramaladni's Magnum Opus

I was able to successfully craft a Ramaladni's Magnum Opus for a Whirlwind Barb, and I would like some advice on the best way to upgrade it.

I am under the impression that I should Enchant the Weapon Damage to Critical Strike Chance (Since Whirlwind is assigned to my 2H bludgeoning weapon) and then Temper Critical Strike Damage. Socket a Grand Skull, then Masterwork it to 25 with Maximum Resource as the Greater Temper.

Is this the correct order of operations? I've never gotten a useful Mythic before and don't wanna mess this up.