The Pike River Recovery Agency has started work to remove the remainder of the 30m barrier, airlock doors and de-watering infrastructure that sits between the 30m mark and 170m barrier.
The process is expected to take four weeks to complete.
Chief operating officer Dinghy Pattinson remains confident they will be able to recover the drift.
"I haven’t seen anything to date that would be a showstopper," he said.
Mr Pattinson says it won’t be until at least the end of September that they will breach the 170m seal.
Over the next eight weeks they will be working closely with experts and WorkSafe to finalise their recovery plans.
On November 19, 2010, 29 men working in the mine died after an explosion at the West Coast site.