the knuckle I have no secret to make it let go. ive used special separators. pickle forks, and a homemade separator. my go to method is turn the knuckle as far to one side as it will go and hit the loop with a 2+ lb hammer as close to the center as possible. should drop out for you.
now the lower ball joint is a PAIN! I had to do mine 2 times (just use moog the first time its worth the cost). the second time around I used a GM ball joint clamp that was made to fit 95-99 GM trucks. If you know anyone that may have one of BEG them to use the damn thing. it fits on the lower a arm perfectly and you can use a impact to bust it loose! if you cant find one of those you can try one of the universal clamps they rent at part stores. I will tell you I had to try 3 different stores to find one that would fit on mine and the one I finally found every time I would clamp it down the damn cup would eventually shift pop off
.... the way I eventually got it off was I lifted the truck up in the air. lowered the it down on a piece of pipe that fit right around the ball joint and hit it a million times with a sledge till it finally popped out. I used every method I could find online before finally doing that. It was like the thing was fused together. hope your luck is better than mine!