If it doesn't come off with the hammer, use a bigger hammer. I remember the first time I used a pickle fork to separate a ball joint. I foolishly was using a framing hammer to beat on the pickle fork. I was hitting it really hard and I got the tines of the pickle fork forced about 1/2 way into the joint, but the joint didn't separate. I got out a 10 lb maul and hit it one or two times and it popped no problem. It's the shock that really breaks the joint loose. If you have a large enough hammer you won't have to work nearly as hard. The weight of the hammer will do the work.
Make sure you leave the nut loosely attached so nothing flies around when you separate it.
If you use a large enough hammer, you don't need the pickle fork, either. I would not use a puller on a tie rod end. Use a hammer alone or with a pickle fork.