Work to clear the railway line at Stonehaven will begin this week.
The line has been closed since the fatal derailment on August 12, which caused the death of driver Brett McCullough, conductor Donald Dinnie and passenger Christopher Stuchbury.
A specialist 600-tonne crawler crane will be brought in to lift the derailed carriages from the site in the coming days.
A 900-metre road and temporary bridges have all be created in order to get machinery to the remote site.
The plan to remove the four carriages and two power cars has been developed by police, rail accident investigators and other agencies and is expected to take several days.
Once the site has been cleared, engineers will be able to properly assess the damage to the tracks and nearby bridge which was damaged as the train derailed.
Until that work is complete, it is not possible to confirm when the line will be reopened.
Alex Hynes, managing director of Scotland’s Railway, said: “August 12 was a devastating day with the loss of Brett, Donald and Christopher in this tragic accident.
“While we will now begin the process of recovering the carriages and repairing the railway, we do so with a heavy heart.
“We will continue to work closely with the Rail Accident Investigation Branch throughout this recovery process so we can learn from this terrible event and help prevent similar accidents.”
Transport Secretary Michael Matheson visited the site today.
He said: “My thoughts continue to remain with the family and friends of those affected by this tragic incident.
“I’m here today to understand the scale of the work being undertaken and to show my, and the Scottish Government’s, continued support for those involved in the investigation, recovery and service restoration.
“The RAIB investigation will ensure that any safety lessons are learned quickly and I will be interested to hear what comes of this and how Network Rail can take these forward in the future. An investigation of this type is so comprehensive and it will now take time to restore the site of the incident so rail services can be reintroduced as soon as possible.
“As we move towards the recovery phase and given the scale of this enormous challenge I would like to thank all those involved for their efforts undertaken at the site.”