Complex sentence: He was a member of the executive committee of Trondheim city council from 1934 to 1940 and in 1945, but had changed to the Conservative Party in 1938, heading the party chapter in Trondheim until 1947.
Split into simpler sentences: He was a member of the executive committee of Trondheim city council from 1934 to 1940 and in 1945. In 1945 he had changed to the Conservative Party, heading the party chapter in Trondheim until 1947.