You can use a pickle fork, but don't just beat the shit out of it because your hammering on the steering box. If it comes out with a few good taps (it usually does) your OK. If not, get a puller on it.
One thing that makes it come off 1000% easier is use a razor knife and needle nose pliers to cut the rubber boot off the ball joint. Then put the pickle fork in there and knonk it off. That makes it easier because the pickle fork is hammering metal on metal, not metal on rubber, which will absorb all the impact
A pitman arm puller is best. A pickle fork will work, but I had to grind the inside of the forks out to fit around the shaft on the box. Def. don't want to bung up the splines. I just used a puller to get it tight and a few taps with the fork to pop my pitman arm off last week.