Renunciation of citizenship
Section 29(2) · 1999 Constitution (2004 edition)
What Constitution says
(2) The President shall cause the declaration made under subsection (1) of this section to be registered and upon such registration, the person who made the declaration shall cease to be a citizen of Nigeria.
This is the 1999 Constitution as published in 2004. Later amendments aren't included yet, so a section may have changed since.
Original source
Official Gazette · CFRN 1999 official PDF · printed page 32. Original document
Release: draft-c8d50d87fae9. Source scope, review and corrections