I would just not dismantle the rack. Ensure that everything inside its securely strapped down and nothing can move freely, not even cables. Ensure that all plugs are safely screwed in the socket or tape them for non screwable ones to prevent to come loose and bang around.

Then fill voids and gaps with bubble wrap or anything light and non scratchy. Wrap everything from the outside with bubble wrap layer to prevent damage from hit or scratch.

Then find or build a big enough cardboard box to fit the rack and call it a day.