Two other stations - Citizen TV and Inooro TV - remain off air.
Rights activist Njonjo Mue said Monday the peaceful demonstration with about 100 protesters was to express outrage against the government's "blatant violation of the constitution".
The government responded to Odinga's event by declaring his opposition movement a criminal organization and investigating "conspirators" in the ceremony.
The government shut down four private TV stations on 30 January after they failed to abide by a state-imposed ban against broadcasting the "inauguration" of opposition leader Raila Odinga as the "people's president".
In the past few days, the government has also briefly detained three opposition politicians, who took part in Odinga's ceremony.
Kenya's government responded to the mock inauguration by shutting down the broadcasts of the country's top three TV stations for almost a week.
Odinga says he, not Kenyatta, was the true victor of a disputed presidential election in August 2017.
Closing the stations has also sparked a flurry of court cases against the government, moving Kenya, East Africa's wealthiest economy and regional powerhouse, one step closer to a possible showdown between the government and judiciary. It was not clear what charges were pressed against the lawmaker, T.J. Kajwang, but he has been released on bail. Larry Madowo, a news anchor with Nation Television, said multiple sources informed him and colleagues that undercover policemen were waiting in the parking lot outside their offices.
Witness Carlos Ouma said a county revenue collector was killed by a stray bullet after police fired into the air to disperse demonstrators in nearby Ahero, Miguna's home town. The original election in August was annulled by the Supreme Court, which described it as "neither transparent nor verifiable".
Kenyatta won the August election, and won the repeat election in October as well after Odinga boycotted it, complaining it would not be fair.