It's the painstaking process of taking apart something that wasn't assembled quite right and putting it back together properly.
For Kara Lang, fingers crossed, the result could be a resurrected soccer career.
"It's just kind of one of those things where I have to try it," Lang said. "Nothing is guaranteed when you really look at it. I just need to know that I tried."
The former Canadian soccer star is mounting a comeback, a chance to put some closure on a career that ended far too soon.
The Oakville, Ont., native, whose two torn ACLs forced her to retire at the age of 24, said she's been overwhelmed by the support she's received since news of her comeback got out late last week, saying "all the encouragement I've gotten is going to push me even more."
Lang could use the push. Rehab hasn't been easy. Since early this year when she put her broadcasting career on hold to commit to rehab full time, she's spent three out of four weeks in Montreal, working with a team of trainers provided by B2ten — a private business group that supports Olympic athletes.
The breaking down-building up process has been tedious, but key. They're "pulling me off that ledge that apparently I was hovering over all the time, of tearing my ACL."
Her workouts, she said, could barely be called workouts. It's been a lot of simple, Square 1 exercises like lunges and squats with no weight. The trainers watch and constantly correct her.
"It's everything from head to toe," Lang said. "They've been looking at my spine and my core strength, my hips, my mobility from all my joints, not just my knees. It's been really slow, but it's been really cool just to see how they've broken it down and all the aspects that were never ever addressed in my two previous ACL rehabs.
"They're basically teaching me how to move in a completely different way. It's very frustrating. But that's what it takes to break these habits that I've developed over the years and some of them I was born with. The idea is that you become a different kind of athlete, more efficient, everything is more compact, basically your risk of injury is decreased."
So far so good. Her trainers had set a goal of December to join the women's team. Now they're talking October. She was flying back to Montreal on Monday to begin a new phase of training. She was told to bring her cleats. She'll finally do some ball work.
"That's exciting," said Lang, who at age 15 was the world's youngest player to score an international goal for a senior side.
John Herdman was the one who asked Lang to consider a comeback.
He knew full well how dangerous she could be, having seen her from the other side of the pitch when he was New Zealand's women's coach.
"We played against them in Singapore and when the first whistle went she tried to score from the halfway line on the kick-off — and she came within an inch of it going in the net," Herdman said, laughing. "I remember thinking 'Oh my god, we're playing against a different level today.'"
Then as Canada's coach, he watched his players embrace their former teammate at the Olympic qualifying tournament in Vancouver where Lang was part of the broadcast crew.
"I didn't quite realize how big a part of the family she was to the team still," Herdman said.
This he did know: he wanted her back in the lineup when Canada hosts the 2015 World Cup. How cool would that comeback be?
"I said to her 'Look, even if I can get you on the pitch for five or 10 minutes in the World Cup, if it's just five or 10 minutes, that's still going to make a massive difference for Canada. Are you interested?'" Herdman said Monday from Germany, where Canada is playing the Germans in a friendly Wednesday.
"We really got into some great discussion, because when a player retires that young, you're thinking, 'Wow, what a waste.' I said, "Look, if there's a way, would you do it?" She hummed and hawed and said, 'I've just got to know that there's a way.'"
Lang said Herdman was a big reason for her gutsy decision. She had been part of the interviewing panel that led to Herdman's hiring in 2011.
"He had me in tears in his presentation. Unbelievable," Lang said. "You know right away as soon as you hear him speak that he's the kind of guy that any athlete, not even a soccer player, but any athlete would want to play for."
Herdman hadn't heard that story.
"That's bloody nice to hear," the coach said. "I get on well with her, she's got a lovely character. I just can't wait to see if we can get her back in a red shirt again."
Lang kept her plans quiet, only a few of her former teammates knew what she was up to in Montreal.
"It was hard the first few months, not telling them all about it," she said. "A few knew, but in March when it was pretty much a shot in the dark, I had no idea what was going to happen or how I was going to react, I really didn't want to come out and make a big deal out of it if it was such a long shot.
"Even now, I'm kind of the mindset where I just want to put my head down and do the work, which is part of why I haven't really been talking about it a whole bunch."
Her B2ten trainers haven't given her any guarantees of success. So far, she's just been training her body. She still has to play soccer, she said. But the trainers did tell her they wouldn't have taken on the challenge without believing there was a chance.
Besides, the attempt is success in itself.
"Talking to friends and family, and people at B2ten, they've helped me understand that it's really not about the end game, it's not about the end result, it's about the journey and the fact that I'm taking this risk," Lang said.
And as Herdman put it, come October when she'll either rejoin her teammates or not, "At least she can sleep easy because she knew it just wasn't possible. Or for Canada, they're going to get a real star back in the team."