Heaven would be a good place to start; a near miracle is needed to pull the South African Police Service - demoralised, corrupt and haemorrhaging officers - back from the brink, and convince the public that the aptly- abbreviated Saps has not already drowned in the rising tide of crime.
It is hard to overstate the lack of public confidence in the police. Everyone has their own story to sum up the force. For some it is the theft, in broad daylight, of the cash dispensing machine from the fourth floor of Johannesburg police headquarters; for others, the identity parade of suspected car hijackers where victims failed to identify anyone in the line-up but easily fingered the officer behind the desk as the ring leader of a hijack gang.
Just yesterday three men stormed a police station in Khayelitsha, Cape Town, and stole all the officers' guns.
If it was not so serious it would be funny. But laughter rings hollow when the rate of violent crime has risen to rival the highest in the world and international organised crime syndicates are reported to be muscling in.
The level of public concern about crime has reached near hysterical levels. In the wake of the murder of Johannesburg economist Dr Ronnie Bethlehem - shot in his driveway by car hijackers - newspapers have called for a state of emergency and South Africans - black and white - are clamouring for a return of the death penalty.
Today, artists will begin work on a Wall of Remembrance in Soweto to commemorate some of the 25,000 people who died violently in South Africa last year. A similar wall was opened to painters in Johannesburg at the beginning of the month and is covered with portraits of victims along with angry inscriptions from families and friends.
Mr Kahn, group chairman of South African Breweries, says he is taking on the most difficult job of his life.
The government must take some responsibility for the crisis after dismissing it initially as "white whingeing". The arrival of violent vigilante groups, like Pagad, pressure from within the African National Congress's own ranks for the death penalty, and growing international concern changed that.
But it is doubtful that a speedier response would have altered Saps' destiny.
The police have been floored by a double whammy, according to Mark Shaw, of the Institute of Security Studies. Since the end of apartheid, Saps has been struggling to transform itself from instrument of state oppression to a non-racist, civilian-friendly police force.
It would always have been an enormous institutional task. But Saps is trying to metamorphose while dealing with an unprecedented rise in crime.
It is, say some, a no win situation. A solution has certainly so far eluded those in charge and led to unseemly public rows between George Fivaz, Saps' national commissioner, and Sydney Mufamadi, minister with responsibility for police.
"People point to the transformation of the South African armed forces," said Mr Shaw. "But the armed forces have been able to change in a time of peace. The police are having to transform themselves under fire."
That can be taken literally. Post-liberation South Africa is awash with guns and the murder of police officers is becoming commonplace. Last year, 73 were murdered on duty while 211 were killed after-hours. Stress also took its toll, with 160 officers committing suicide. Alienated by necessary change and increased dangers on the job, officers are queuing up to leave. Many stations simply fail to function for lack of manpower.
Mr Kahn can at least take comfort in the lifting of a moratorium on police recruitment.
Fresh blood is badly needed. "Under apartheid the police did not really police," says Antoinette Louw, a criminology researcher at the University of Natal. Detectives generally beat a confession out of black suspects.
Today South Africa sits at the the top of international crime tables. While international crime comparisons should be treated with caution, Ms Louw says South Africa undoubtedly has a very high comparative rate of violent crime.
She traces criminal violence back to the high levels of violence in the home, and in turn attributes that to the wholesale break up of family and community under apartheid.
But just three years after the election of South Africa's first democratic government, legacy-of-the-past explanations are already unfashionable with a public demanding quick and simple solutions.
While Ms Louw believes the rates of some crimes are levelling out, she will not hazard a forecast as to when crime will begin to fall.
Mr Kahn's contract is for just two years. Surely too short to make a difference? Long enough in one of the country's toughest roles, says Ms Louw. Mr Kahn will want out before his term is up; that she can confidently predict.