This mechanic has always been a challenge, you need to hit him with frost magic until he solidifies and then you have to melee damage him hit full health within 10 -20 seconds. It’s a really hard solo. Just make sure your weapon has + attack damage enchants and you should be able to do it.
The freeze part isn’t even the problem. I can freeze him with my enchant. The melee damage part is the problem, classes like Ret do too much holy/spell damage, not enough melee damage. Even though we’re considered a melee damage dealer.
Yeah, I know I am saying remove all of that mechanic for Legacy Content runs.
I think it’s kinda cool to keep old bosses like this with weird quirks as long as they can still be solo’d. It’s optional anyway so if there’s something you specifically want off of THIS boss, I don’t see it being the end of the world learning how to solo it for your spec.
Seems like most classes can solo it with a fast attacking one-hander of some kind with drums/haste buffs.
Thought I would update: Got the gloves. I went through the raid on my unholy DK with just the Deathfrost enchant. Killing boss on that character was easy (army of the dead after frozen). So now all I need is just the “quest items” so I just have to do it weekly for rep. But still, I don’t think I should have needed to go through the hassel of using a different class.
Get the elemental force enchant, ,make a heirloom, and enchant that baby. 
dont need enchants to freeze him
there a toy gun that freezes him
If memory serves - snowballs will do the trick. Admittedly it has been a while since I’ve tried.
If blizzard would cease nerfing previously utilized items such as “Crate of Kidnapped Puppies” to where the summons only do 1 dmg to the boss bc the boss dodges all of their attacks…then this wouldnt be such an issue. They have taken steps in the past to make encounters easier to solo. Why they havent done it for this guy is beyond me. Its simply a settings change. All the mechanics such as reliance on frost dmg are done away with, Mage and dk have frost simply for cosmetic purposes.