Police had been in charges of the operation since last month's explosions which resulted in the loss of 29 workers at the mine.
Yesterday contractors capped the mine's ventilation shaft using a helicopter to fit two semicircular plates in place.
It is hoped that this will trap the carbon dioxide being emitted by the Gorniczy Agregat Gasniczy (GAG) machine at the mine's entrance to prevent more fires.
Superintendent Dave Cliff said today the next phase in attempting to recover the bodies would involve dropping piping into the mine shaft to pump in pure nitrogen using a nitrogen-generating device to increase the cooling process.
The large machine is due to arrive in Greymouth later this week from Australia.
"We need to work out the most effective way to transport it in to the country. There is no manual to this, it's a matter of listening to experts," Mr Cliff told Radio New Zealand this morning.
"What we have to do today is install piping in to the top of the shaft, we are hopeful that will be transported today and then it's got to be laid."
Police are working through a staged handover to Pike River Coal but Mr Cliff said he was committed to handing over the operation in a safe state.
Mr Cliff said the nitrogen would ensure the mine remained as safe as possible with less risk of any more explosions.
The GAG unit would be switched on and off as required when levels of oxygen rise.
Mr Cliff said police would be meeting with the victims' families in Greymouth later today to discuss latest developments.
