Chipotle Mexican Grill Inc. shares dropped in after-hours trading Wednesday after the restaurant chain's top executives detailed restructuring plans that include closing dozens of locations. New Chief Executive Brian Niccol and other executives held a conference call Thursday afternoon to discuss changes under the new management team, which included plans to add delivery options to the chain's mobile app and areas specifically for picking up food at stores. Shares turned lower after Chief Financial Officer John Hartung detailed the costs of restructuring and revealed that Chipotle plans to close 55 to 65 stores. "In aggregate, we expect these costs to be in the range of $115 million to $135 million," Hartung said, with $50 million to $60 million recorded in the second quarter and most of the rest in the second half of 2018. Hartung said about half of the closures will happen in the next 30 days, while those closures that involve more complicated lease buyouts will stretch longer. Hartung stressed that Chipotle was not updating nor reaffirming its financial guidance, but outlining non-recurring charges. Shares declined 2.9% in late trading, after closing with a 1% decline at $457.24. The stock has rebounded since Niccol was brought in from Taco Bell as the new CEO, and has gained 58.2% so far this year as the S&P 500 index has increased 1.9%.