Complex sentence: In September 1987, as a part of a station makeover spearheaded by a new promotional campaign that began running that summer, a new logo was introduced that consisted of a numeral "7" composed of seven white dots and encased in a blue circle.
Split into simpler sentences: In September 1987, as a part of a station makeover spearheaded by a new promotional campaign that began running that summer, a new logo was introduced. This logo consisted of a numeral "7" composed of seven white dots and encased in a blue circle.