you cant just jack the truck up and shake the wheels like the old days. the front end has to be loaded with the wheels off the ground (weight of the truck on the lower arms) then you simply use a long pry bar and in the correct places pry up and down while checking for movement from the balljoints.
either way 4x4 or 4x2 checking them is the same and you have to remove the steering knuckle to replace the lowers.
now on older twin I beam trucks all you had to do was jack the truck up and wiggle the tires.
I dread this when it comes time for mine to be done. I talked to a shop today that quoted me 800 to do lower and upper complete job including the alignment. Damn why cant parts be made that dont break. I hate not being mechanically inclined and Zach won't come help me either.