Shira Goodman, CEO of Staples: Goodman says that her office supplies company had a “bona fide crisis in terms of how we sell and what we sell” as more purchases moved to e-commerce. That led Staples to its decision to go private and sell itself to private equity firm Sycamore Partners earlier this year.

Goodman, who is a 25-year Staples veteran, says that as someone with a long tenure, one of the hardest things was figuring out how to let go. “You have to destroy what you built,” she says, adding that your perspective should be, “I get to do this versus I have to do this.” “I feel like I’ve learned more in the last year than the prior five years,” she says.

She believes there are four things leaders don’t say enough: I was wrong, I don’t know, I need your help, and thank you.

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Mary Dillon, CEO of Ulta Beauty: Dillon says that in her first month on the job as CEO of Ulta in 2013, she started picking up clues that the company needed to reinvent itself internally. “It was not a great culture in terms of people being heard and listened to,” she says.

Dillon pushed to create a collaborative environment rather than one rife with internal competition. “I won’t put up with any of that,” she says. “As a woman with that style, it can come off as not decisive enough.” So far it’s paid off: Ulta (ULTA) has been hitting double-digit percentage sales growth every quarter.

Margaret Keane, CEO of Synchrony Financial: Keane became CEO of the lender and white label credit car issuer when it split off from General Electric in 2014. She says that as the company figured out how to go it alone, she had to publicly keep up a persona of confidence.

One benefit of a transformation, Keane says, is that “some real talent emerges as a result.” She pointed to her CIO as an example as she dealt with a tremendous workload during Synchrony’s (SYF) separation from GE (GE). “She knew what she wasn’t strong in and hired people more senior than her in some areas,” she says. “They helped her deliver.”

Christa Quarles, CEO of OpenTable: Quarles says that OpenTable (OPEN) had a very “command and control” culture. But as a leader, she says you have to be willing to receive criticism and feedback in order to give it. “The executive team trusts each other,” she says. “We’ve all gotten to a place where we can say the thing on our mind.”

Shideh Sedgh Bina, founding partner of Insigniam: The Insigniam founding partner, who works with CEOs and c-suite executive on transformation, says that in every post-mortem she’s done over 30 years the No. 1 lesson that comes up is that the company did not “get rid of the wrong people fast enough.” Her advice: “I would look for people who are not aligned.”