The qualified electors or legislative body of a noncharter code city may provide for the exercise in their city of the powers of initiative and referendum, upon electing so to do in the manner provided for changing the classification of a city or town in RCW
35A.02.020,
35A.02.025,
35A.02.030, and
35A.02.035, as now or hereafter amended.
The exercise of such powers may be restricted or abandoned upon electing so to do in the manner provided for abandoning the plan of government of a noncharter code city in RCW
35A.06.030,
35A.06.040,
35A.06.050, and
35A.06.060, as now or hereafter amended.