Complex sentence: There is no late night service along the entire J line, however part of the L-Owl and N-Owl diesel bus lines run on Market Street between Church Street and Steuart Street.
Split into simpler sentences: There is no late night service along the entire J line. Some of the route is covered by the L-Owl and N-Owl service provided by diesel buses run on Market Street between Church Street and Steuart Street.