The UNLF and its military wing UNLA removed Idi Amin from power with the support of the Tanzania People's Defence Force on April 11, 1979.
He was later appointed Assistant Secretary in the office of the Prime Minister of Uganda and received promotions, including one for saving the life of the King Sir Edward Mutesa II from an assassination attempt by Idi Amin in 1966.
In 1977 his maternal uncle Archbishop Janani Luwum was murdered along with two cabinet ministers, Erenayo Wilson Oryema and Charles Oboth Ofumbi.
Opira played a key role in founding the UNLF and facilitating the Moshi conference that led to the fall of Idi Amin.
He died of heart failure in November 2000 and was survived by his widow "mama Sammy" whom he married on New Year's Eve 1955, and children.