why would you not get the bus? 482/490 use sheffield way stop.

maybe first thing (i.e. before 0600) the bus is a bit tricky if you have lots of bags, but otherwise it is fine.

if not getting the bus and not having much luggage, i would walk to hatton cross and get a t5 tube from there.

if i did have luggage i would do elizabeth line to central, then HEX/elizabeth to T5.