This quest is given by Warmaster Laggrond in the Alterac Mountains at 62,59. I would recommend a group of at least 3 for this quest to be completed effectively.

Once you enter Alterac Valley, the entrance to the Wildpaw Cavern is located at 52,89. Once there, you need to fight your way in to retrieve a Frostwolf Banner (https://classicdb.ch/?object=179025) for the quest.

The banner itself is located at 50,93, deep inside the cave. There are many mobs spaced closely together around the level of 52-56, so it is very possible that you will be pulling 3 at a go.

NOTE: Watch out for Alterac Yeti (https://classicdb.ch/?npc=13959), a level 61 elite wandering the cave.

The reward from the quest, Frostwolf Insignia Rank 1 (https://classicdb.ch/?item=17690) allows you to port back to Frostwolf Keep once every 2 minutes.

This trinket is upgraded as you gain reputation with the Frostwolf Clan.

Neutral: Rank 1 (https://classicdb.ch/?item=17690)
Friendly: Rank 2 (https://classicdb.ch/?item=17905)
Honored: Rank 3 (https://classicdb.ch/?item=17906)
Revered: Rank 4 (https://classicdb.ch/?item=17907)
Exalted: Rank 5 (https://classicdb.ch/?item=17908)

You missed Rank 6 :)
http://classicdb.ch/?item=17909#M0z

The surrounding mobs are level 66-68 in the level 61-70 version of Alterac Valley, three is standing near the flag and you'll have to fight them at once. Bring a friend, or a potion, if you are playing a class that can't heal yourself. The wandering Yeti is level 71, he hits for ~1500 on leather, so keep your eyes open.

I just solo'd this quest as a 66 Affliction Warlock. Of course, everyone in the 61-70 bracket is too busy telling you how long ago they finished the quest to actually help you complete it. So, a few failed battlegrounds later, I finally mastered the art. I assume most classes with mass CC could use this method (i.e., Priests with Psychic Scream, potentially a Frost Mage's Frost Nova, etc.)

Basically, just zerg rush into the entrance of the cave. Rush straight between the two big groups on your left and right, fire off a Howl of Terror (if you have it on instant cast) once you've got a group behind you, fall off the ledge and head right. You'll come across a narrow passage with a couple decent-sized rocks against the right wall in the center of the passage; try to die as close to those rocks as you can. Once you're dead, release, and don't resurrect at the graveyard. Run back to your corpse in the cave, and try to resurrect by that rock, preferably closer to the entrance of the cave, and hug the wall. Check ahead of you to make sure you won't aggro the knoll that's standing farther back in the passage when you resurrect.

Now, there's a gnoll that patrols the ledge immediately above the rocks I'm speaking of. If you keep an eye on him, you can resurrect just as he's walking away and you'll have plenty of time for a Voidwalker before you make your second zerg rush. Not at all necessary to summon a Voidwalker here; I didn't use one for the entire run. Just make sure he's far enough down his partol that you don't aggro him when you resurrect, or it will screw up your second rushS bigtime.

Once you've resurrected, catch your breath and rush straight down the passage, and take a hard right. You'll see the banner in the back on the passage, on an island in the middle of a frozen pond. The gnolls will likely kill you before you get there, so just die close enough that you can resurrect on top of the banner. Die again, and make one last corpse run, making sure your mass CC is completely cooled down.

As soon as you resurrect, gather up the five gnolls in the area of the banner (1 on the island, and 4 around it), try to get these as close to the center island as you can, and fire your CC. At my level, Howl of Terror lasts for 8 seconds; I was able to loot the banner in what appeared to be 6 seconds. So, I had about enough time to fire the CC, jump on the island and loot. So, even with lower-rank Howl of Terror, you should be able to take the banner with just barely enough time to spare. Just be careful not to do this too close to any of the groups beyond the icy pond, or you risk grabbing an add and spoiling the attempt.

So, assuming you don't mess up, you can easily get this banner in 3 deaths, assuming you let the gnolls kill you the last time rather than escaping. Try to do this as early and as quickly as you can; if you Allies capture your graveyards in the south and your team is already up north, you could end up running the length of the instance back to your corpse in the cave. I attempted this a few times and didn't even have a change to finish my attempt simply due to the fact that the game ended too quickly. It may take a few instances before you get the cave down, but once you do, you should have no trouble.

Good luck getting your Insignia!