first step: dismantling the locomotive

remove the inked inserts and take clear ones

contour line with black wash and light grey mixed like a wash over all with airbrush for a sun bleached look. (be careful, not too much grey)

black wash and light grey drybrush for trucks and fueltank

installing sunshades, black powder for exhaust and brown for rust (take a soft paint brush)
seal with a matt clear varnish

the ptc antenna is from Atlas