Here's how I've done mine. Remove the cotter pin, break the castle nut loose but don't remove it. Leave it about half way off. Take a jack and put it under the brake rotor and lift it slightly. Not enough to pull the car off the jack stands but enough to put some weight on the suspension. Take a large hammer and smack the LCA where the ball joint goes through. The vibration from the hammer and the stress from the jack are usually enough to pop it loose and if your careful not to hit the boot with the hammer, the ball joint shouldn't be damaged. You can see and feel once it pops and if you leave the nut on, the spindle won't go anywhere either.