Complex sentence: Dennis Tanner returns after 43 years where he met Sophie Webster and Sian Powers volunteering at a soup kitchen he after walking on the street he spots "Dennis Tanner 1951" that he had carved into the window sill of No.11 many years before.
Split into simpler sentences: Dennis Tanner returns after 43 years where he met Sophie Webster and Sian Powers volunteering at a soup kitchen. Some time later, after walking on the street he spots "Dennis Tanner 1951" that he had carved into the window sill of No.11 many years before.