I have been a longterm member of the United Church of Canada (1965) and have served it at many levels. My first encounter with the willingness of the Church to change was in 1965 when the denomination replaced the W. C. Cook Sunday School material with the New Curriculum.
(http://www.united-church.ca/history/overview/timeline)

The next really big change took place in 1988 when General Council voted to: