for Piccadilly- the Metro tram is the easiest - the railways stops are as follows:
Altrincham - Navigation Road - Timperley - Brooklands - Sale - Dane Road - Stretford - Old Trafford -Trafford Bar - Cornbrook (for stops up to Eccles and the Lowry Centre) - G.MEX -
St. Peter's Square - Mosley Street - Piccadilly Gardens - Piccadilly (Station)
then there is another route which is the same from Altrincham to St. Peter's Square then - Market Street - Shudehill - Victoria Station - towards North Manchester including stops at Crumpsall, HeatonPark, Prestwich, Besses O' The Barn, Radcliffe, Whitefield, and terminating at Bury