Complex sentence: The Edinburgh, Leith and Newhaven Railway provided access to the pier for ferry passengers and bathers from 1842 from Trinity railway station, the original terminus of the line, which was replaced in 1846 when the line was extended to the new harbour at Granton.
Split into simpler sentences: The Edinburgh, Leith and Newhaven Railway provided access to the pier for ferry passengers and bathers from 1842 from Trinity railway station, the original terminus of the line. This was replaced by a new station in 1846 when the line was extended to serve the new harbour at Granton.