Help-What's the trick for removing gear arm from center link?

Another method that works good for me (especially if you don't want to replace the boot) is to whack the center link with a hammer where the pitman arm stud passes through. Put the nut back on loosely (in case your miss with the hammer! :-) ) squirt the whole area with penetrating oil, and give it a couple of good whacks right on the side of the center link. I should pop right loose.

That almost always works for me. Rarely use a pickle fork. But I work on cars in a part of the country that don't have the weather's elements on them that make things super stuck together.