You need a tank for this, preferrably three people.

As of 2.3 this isn't flagged as a Group quest.

Mai'Zoth isn't Elite, but he has quite a posse of helpers surrounding him. Did it with two paladins (48 and 45) and it was a near-run thing because we pretty well stumbled into the whole mess, so...bringing friends is still a good idea.

This was really easily. Don't bother trying to pick off the guards one by one to get Mai'zoth alone (its not going to happen). But luckily i killed the spellcaster first before i realized this, so when the 1st add respawned he was another melee. So all i had to do was sneak up behind Mai'zoth and pop evasion, 5pt cb evisc and imp kick rocked mai'zoth, and i sprint+vanish'ed away after i looted. :)

I just soloed mai'zoth by kiting him towards grom'gol.

hardest part is to clear all the aggro on they way to him, you have to be super fast or they will respawn. beware of the 2h axe guys they hit damn hard, had to kite some of them in the valley before the cave.

now here is the tricky part(hunter only):

as you enter the cave take the left path and kill clear aggro, halfway up to mai'zoth i felt like i have to hurry as some of the ogres outside already respawned. I targetted one of the guards around mai'zoth through the wall (couldnt see them, because i still had some ogres on the way to him) make sure to not target mai'zoth, you will need to draw aggro later.
Now send pet on the guard (ogre lord in my case), and as soon as your pet takes/deals damage, put it on passive. when it is back at you, send it to attack again. You now have to arcane shot mai'zoth as fast as you can to draw aggro, dot him, maybe fire trap, and run out of the cave with aspect of the cheetah turned on. your pet will die a few seconds later giving you some breathing space.
after leaving the cave i had to instantly turn right und run up the hill because of ogre spawn. beware of tiger aggro if you use this way.
Mai'zoth himself wasnt hard at all, he did cast some fire aoe stuff but never hit me, i also saw a frost cast animation but nothing happened, dunno whats that. He died pretty easy when i was around the goblin-shredder guys.

Also found the key for another quest on my way into the cave.

This quest is impossible to solo, even as a hunter. You will need 4-5 lvl 40+ to do this quest, Mai'zoth is located in the last room in the cave, he got 1 guard. The tactic is easy just MC or sheep the guard and kill Mai'zoth, kill the guard after.

Solo'ed at a level 45 Paladin, 0/25/11 Spec using Horned Viking helmet to stun his add :) Was fun

Soloed as a 50 combat rogue. Sapped 1 guard, popped evasion + adrenaline rush and just dps-ed the hell out of boss while being hit by boss + 1 guard. I was careful to interrupt all his spellcasts... still had to use a potion before i could finish him off though

where to start this chain ?

You start the chain in the Grom'gol base by clicking the cauldron next to Kin'weekly. It is a long chain and this I am guessing is near the end.

At level 45:

You gain 5050 experience.
Your reputation with Darkspear Trolls has greatly increased.

cosmos position 53:28, deep in the cave, two lvl 45 elite guards that aggro same time, and he is a lvl 47 elite, to be continued...

Solo'd as a 45 mage, Sheeped one of his bodyguards, brought the other down asap then ran my ass outta the cave until out of combat, started again, sheeped his last bodyguard, killed Mai'zoth ASAP

Isn't flagged anymore as Group quest idd, and I risked to solo it as a 43 frost mage.

First time I got killed quite fast, the sheep resisted, my ice barrier failed immediatly , ... no chance.

Scnd time I sheeped again his 45 Lord and focused immediatly on the spellcaster. At that moment, Mai'Zoth wasn't pulled at all .. he didn't move .. he didn't aggro. So i continued blasting the spellcaster down.. afterwards I waited for my mana to regain a bit and sheeped the Lord again. Then I fully attacked Mai'Zoth who went down quite easy tbh. Had some crits so .. mayb lucky. When the Lord came out of sheep I had regained plenty of Mana and Hp to finish him off.

Guess I was lucky, or maybe this is a good way of handling :)

solo'd as a 44 blood elf shadow priest...not too easy, I died a couple times but eventually got it done alone.

Soloed as 44 undead shadowpriest.

Shadow form, full buffed (innerfire, touch of weakness, powf). Dot Mai'Loth with Devouring plague and Shadow word : Pain, shielded mind blast, mind flay, (go close to the caster, so you can mass fear them all) , reshield, mindflay, mind blast - shield , loot and run out!

Just ignore the two adds (the spellcaster and the lord), nuke Mai'Loth and run the hell out of there...

Got 5800 xp at lvl 45

Easy as a 45 mage
Fire ward / manashield -> Pyro, Fireball, Fireball, Fireball etc
All three dead with no dmg taken

Gave this a shot as a 48 Shaman (Enhance).

Basically kept purging the casters shield off as i worked them down first, and had a Stoneclaw and a Grounding totem up as much as possible.

Ended up them all dead, and myself on 30% health, Not too tough.

soloed as a 43 prot pally, first try killed mage and mai'zoth and looted then died from the big guy, it's a bit difficult but soloing is definitly plausible

It might have been bugged or something, but when I pulled Mai'Zoth, only him and one of his guards came (the one on the left). I was easily able to solo him as a 46 Druid and on previous attempts when I would rush in, I would get all three of them on me.

Solo'd as a 43 Assassination rogue,

Started out with a distract, sapped one of the guards, blinded the other.

Cranked cold blood and ambushed Mai'Zoth, burned him down as quickly as possible and vanished.

Quest complete.

Solo'ed as 47 enhance shaman. He is in the back of the cave, with two maulers near the entrance to his 'room' and then two lords nearby. Should be able to get to him easily without pulling too many on you. Then pull the guards with a LB, and go after Mai'Zoth with everything ya got. Then just astral recall yourself back to Grom'gol or Booty Bay, or wherever and proceed to the camp.

Did this as a rogue by sapping the Lord and just going all out on Mai'Zoth. When he died, I looted and vanished...
The easy way out...

Solo'd as a 45 shadow priest, one word: "Mind Soothe"

All three pulled for me. Couldn't do this as 45 druid. Coming back at 46, might do it with a ghost run.

I was easily able to range pull his two guards without him.

Killed them drink/ate up and went for the big guy!