  The program of upgrade of the Spherical Neutral Detector for future
experiments at a new VEPP-2000 $e^+e^-$ collider is presented. Modernization
includes upgrades of electromagnetic calorimeter, tracking system, detector
electronics, data acquisition system, and offline software. It is also planned
to equip the detector with two new subsystems: particle identification system
based on aerogel Cherenkov counters and external electron tagging system for
$\gamma\gamma$ physics.
