The first step in taking over a pack, is killing the leader that is the same gender as you so you can mate with the other leader.
Obliviously, it's nicer to just find a pack that has lost a leader, but that would be a very lucky find.

So first, choose your wolf and what map you will be in. Neither really matters, but don't choose Lost River if you want to do this the fast way. Since my wolf Rowena is a female, I will need to kill the female leader of a pack.


My wolf, Rowena.















Once you choose your wolf and have spawned into a map, choose which pack you want to take over. Once you've chosen, or picked at random (I usually just picked the closest pack), go to the edge of the pack's territory and sleep.
This is the tricky part
When you wake up, let the wolves come near you and then quickly go to the Known Wolves section and check who came.

If it's just subs/yearlings/pups, or the leader whom you want to eventually mate, run away, sleep briefly or just go to a different part of their territory, and try again.


If it's the leader who is the same gender as you, however, even if there are other wolves (it's near impossible to get them alone) attack. Keep attacking the leader, even if others attack you. As soon as you have killed the leader, run out of their land.
Here I am, killing the female leader Nightmantle. This was during one of my earlier attempts that failed, but I don't have footage of me killing Starfield, the leader whom's pack I eventually got to lead.

Now this is the part that can be done very differently.

Many people just wait around outside the pack's territory, sleep a few times, and keep howling until they hear the howl of a interested-pack-wolf, which may be the leader, and then enter the territory to see if they are ready to mate.
Important Note: Entering their territory too often can delay the leader's agreement and I've had them continue to be aggressive when I keep sleeping in their land, so make sure to stay out of their land most of the time once you have killed one of the leaders.

I tried this several times, but the pack was always hostile and it never worked for me. I'm sure it works for some people, but I wasn't having any luck. I was probably entering their land too often, now that I look back on it.

But then I heard that someone had found out that if you leave the map, then return, enough time passes that the remaining leader should be courtable. I tried it out, and it worked.

So, first run to the closest move-to-another-map area. I was on Amethyst Mountain and dealing with Wapiti Lake Pack on the left side of the map, so for me, this was the border to Hellroaring Mountain.
Then, turn around and run straight back to the other map. So, for me, I went back to Amethyst Mountain.
By the time you get back to your original map, enough time should have passed.

Now that you are back in the map you began in, go straight to the territory of the pack you dealt with earlier. Just before reaching their border, I howled, and the pack leader appeared to respond. If they don't howl, just go to their territory and sleep. I tried this as well, using a earlier save, and it worked just as well, the leader being there when I awoke.

Here is what it looks like when a pack wolf howls, showing they are willing to court, in a pack who's land is orangey-brown. If the pack has green land, the pack-wolf-howling symbol will be green, and so on. This may be a pack leader, or a sub, so you have to find how who is howling to find out if they are who you are looking for.






I then went in the direction of the howl and got this pop-up.
Doing a quick play-bow, to show them I was friendly, I began to court the leader. His son, Star Speckled, was also interested in me as a mate, but I ignored him and focused on Hourglass.

Once his heart-marker filled up, he became my mate. I got a couple pop-ups, and also the achievement.
Personally, if he hadn't been a leader I probably wouldn't have mated him. He has practically the same coat as me, and is a one-star diversity. But I was desperate to get a pack leader mate. Good thing I don't mind having a small number of pups :)

Now that you have mated, the screen will fade to black and then the whole pack will be there, ready to welcome you to the pack. This is a good time to see all their coat colors and name the ones you haven't already named/met. Pack Affinity will be 0%, so you will have to spend sometime socializing with them and getting them to know you before anything else.

If you, like I did, do this with a wolf you have spawned in fall, in the time-to-find-a-mate season, the pack will be at the Young Hunters stage and you will have the pack's partially grown pups to raise. Have fun with your new pack!

If you are going to try this, good luck! And if you already have and have had it work, congratulations :)
It took me forever to succeed and thankfully Rowena is a very patient wolf, since she's the wolf I always use when trying out new things and trying to get achievements.

Q: Should I be worried about other dispersal wolves mating with the leader after I kill their mate?
A: Yes, it is a reasonable worry. I never had it happen, despite meeting female dispersal wolves at least two times, but in case it does happen, just make sure to create saves. Personally, I created a save as soon as I killed the female leader, and another save shortly before leaving the map (if you are doing it that way) can be helpful. That way, if the other leader mates with a dispersal other then you, you can go back to that save and hope that this time the amount of randomness insures that it doesn't happen. Unless you don't mind killing them as you did to the leader before them.

But no, I would not suggest killing every dispersal wolf you see whom might do this. It wastes time, energy, and in the end the chances of this happening are small.

Q: What if when I kill one leader, the other disperses and either the pack disbands, or a subordinate takes over.
A: Unlikely to happen, but yes, it can. If the pack actually disbands, you will have to try with a different pack or start a new game. If a sub takes over, you actually may be lucky. If they are the opposite gender as you, you may be able to mate them before they get a mate. If not, begin again, either by going after a different pack, starting a new game, or going after the same pack as if you were just beginning.

If you have any tips of how you succeeded, or if you see anything I said that you think to be incorrect, please tell me. This is simply how I manged to do it, and I'm sure everyone's experience is different.