It is the first time in Nigerian history that power is changing hands – from the People’s Democratic Party (PDP) to the All Progressives Congress (APC) - democratically.
Even though attendance is by invitation only, Buhari’s nationally televised swearing in ceremony is likely to ratchet up the Buharimania that has gripped Nigeria.
"It’s a milestone," said Ibim Seminitari, an APC member and Rivers State government official in an interview. "It’s also exciting because it’s coming at a time when Nigerians are feeling very positive about change."
The charismatic Buhari, a former governor and oil minister who enjoys the aura of an elder statesman, is sometimes described as "messianic" and expectations are high.
"Average Nigerians, Nigerians on the street, are quite certain that with Buhari’s inauguration things are going to start improving magically and immensely," noted writer and policy analyst Ayo Sogunro. "You cannot blame them because the last five years of President Goodluck Jonathan’s administration has been [adversely affected] by his personal inefficiency. They believe Buhari’s personal efficiency will now [positively affect] the administration as a whole."
Buhari, 72, is faced with a daunting task.
He is expected to tackle rampant corruption, wage war on Boko Haram insurgents in the north-east and resolve economic woes stemming from the collapse in the price of oil, which accounts for 70 per cent of government revenue.
Some Nigerians are buoyed by early, if symbolic, signs of change at the top. When the president elect recently traveled to London, he refused to ride in a Rolls Royce, chosing instead a Toyota Camry – to the dismay of the Nigerian High Commission staff.
"Buhari is beginning his term well by sending the right messages to all those serial swindlers who are clothed, fed and wined by Nigeria’s scarce resources," wrote Nigerian publisher Chido Nwangwu in an article. "I believe Buhari's austere and Spartan approach has made the maniacally greedy and indulgent political cabal very uncomfortable."
Buhari has been trying to lower expectations.
"Prior to the elections he was saying how this and this was going to change but as soon as he won he calmed down a bit," explained writer Sogunro in an interview. "We expect that he will now say to Nigerians 'you have to be patient,' 'you have give us time,' 'we are building up from scratch.'"
Nigeria has been hard hit by the fall in oil prices, the drying up of foreign reserves and an external debt that has swollen to 9.46 billion dollars (8.67 billion euros). Although the economy is projected to grow at almost five per cent this year, the situation has been so dire - "totally bleak" according to analyst Sogunro - that the federal government has been struggling to pay its employees.
Many commentators hope that the new boss will trim a bloated cabinet that has at times included some 60 ministers, an early sign of his willingness to put his change mantra into practice.
"Some ministries have up to three ministers!" remarked analyst Bello. "The cost is so high, maintaining their offices, their vehicles, their aids. This is a critical issue that people will be looking at the first few days. In the past, the president did not know how many special assistants he had because the jobs were just given out to satisfy political purposes."
Some are concerned that Buhari, a former general who took part in two coups (in 1966 and 1983), may be tempted to revert to tried and tested methods.
"To succeed in tackling [Nigeria's] knotty problems, he will need to behave like a dictator," one former army officer told AFP.
This resonates with critics, particularly from outgoing President Jonathan's PDP, who have even suggested: "Once a tyrant, always a tyrant."
The inaguration ceremony at Eagle Square in Abuja on Friday is set to be attended by dozens of heads of state, including South African President Jacob Zuma whose presence has caused ripples due to the recent xenophobic attacks in his country.
The National Association of Nigerian Students (NANS), which has been vocal about attacks targeting Nigerian nationals, has said that Zuma is not welcome in Nigeria.
But it has backpedaled on plans to protest his presence at the inauguration.
"We intended to picket at the [Abuja] airport but we decided not to picket because our government have spoken to us [saying] that it would tarnish Nigeria’s image," said NANS president Tijani Usman in an interview.
As they watch the swearing in ceremony on TV, many Nigerians may harbour hopes that their country, having been able to conduct federal and gubernatorial elections, will finally do better under Buhari’s stewardship.
"It means that indeed Nigerians are able to take care of their internal affairs in a manner that will give hope to the entire country, to the entire continent of Africa and indeed to the world," observed APC member Seminitari.
Follow Michel Arseneault on Twitter @miko75011