Complex sentence: First Great Western operates hourly Cheltenham-Swindon with two-hourly extensions to London Paddington, via the Golden Valley Line through Stonehouse, Stroud and Kemble.
Split into simpler sentences: First Great Western operate an hourly Cheltenham-Swindon with two-hourly extensions to London Paddington. These services operate on the Golden Valley Line via Stonehouse, Stroud and Kemble.