Your mast with the
rigging attached will weigh a few hundred pounds, and no, not likely to unstep without a crane.
However, there is surely no need to unstep to replace a spreader boot. Replacing is a simple job from a bosun's chair... a device that should be on every
keel boat IMO.
Purchase of a chair will be much less than the crane fee, and you will be
learning a needed skill.
Jim