My mate pushes buttons for a living for EWS. He has a 'contract' of hours per year, anything over the contracted hours is paid as overtime. Usually works 3 weeks on then a week of rest days (which he usually works), contract runs April to April he's on about £35k per year basic but he breaks his contract in about Jan so has a couple of extra months to make some more cash, usually ends up pocketing about £45k per year.
As for driving being easy, it aint. He took me down to the yard (after having done a 2 day Rail Safety course he sorted out for me - was bored and had a few days off) and showed me what he does, just starting them is a major undertaking, lot's of switches to turn, levers to pull, everything you touch is covered in **** and weighs a ton etc. Driving them is constant concentration, no radio in the cab so nothing but diesel engine to listen to for anything up to 14hrs! He has been doing it for a good few years, then slipped up one day and missed stopping at a signal by 10ft, he got ordered to wait for relief then got taken away and breath & drug tested, sent home on paid leave whilst a tribunal was called, eventually got some kind of warning for it and a permenant black mark on his record with his licence being downgraded to a point where it will take him 5yrs to get it back to the level he was at! It ain't a very forgiving job.
He started as a trolley dolly for GNER then took the psychometric tests showing he was suitable material for EWS then spent a few years shunting wagons round a coal yard until being able to go out on the track.