The upgrade will include changes to the shops, improvements at the taxi rank, moving the existing ticket office and a new first-class lounge.
There will also be improvements to the entrance of the station which has been at the heart of the city for more than 150 years.
Changes will be made so the work can be carried out with no disruption to the queuing systems in place for either the station or attached Union Square.
However, during the work the short stay car park will be closed and the taxi rank will be moving to the College Street multi-storey car park as of Tuesday.
And steps between Union Square and Guild street will be closed from Monday
Services between the Granite City and the central belt remain cancelled following the fatal derailment at Stonehaven.