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They don't need to be pressed in?

No they are bolted in, only 5 nuts to be removed.

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If you do one at a time, I assume the one opposite the one your replacing will hold everything together right?

Correct, though using a floor or bottle jack will be helpful to support the weight, once you disconnect the upper or lower ball-joint.

More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed