watch out, those sort of windows can catch you out. If it is the lift out sort you will :-
lift out and place on the floor on a drip surface (not carpet)
clean one side
turn it round
clean the other side
turn it back round
put it back in the right slot without touching the inside
then take it out again and clean the inside of the window :

things that eat up the time are:-
getting the damn things out
putting them in the wrong way around and getting the damn thing out again
putting them back in and seeing marks and getting it out again
putting down drip cloths ( usually on immaculate cream carpets)
when you get halfway round they will say can you clean out those slots as well
secondary glazing is a nightmare, it is always stinking dirty.