Should your washing machine need to be disconnected in order to either replace or repair it, the routine is not very complicated. It is just that there is a very high risk if it is not done in the right way you will have a flooded kitchen or utility room. Before you start if you are not confident always call a professional like A Stratford Plumber can fit a new washing machine. Firstly pull the machine away from the wall and unplug the mains electrical supply. If the machine has two hoses (hot and cold), turn them both off and disconnect the hoses. This can easily be done as they should be fitted with chrome type isolators on each line. For isolating move the lever on the isolator 90°, so it is across the pipe do this for both, they are, blue for cold and red for hot. New washing machines are now mainly cold water fed only. Use a container handy to collect any excess water from the valve. You should be able to unscrew the hoses by hand, (have a wrench close by). Check that isolation valves are closed and not leaking. If there is a tap (isolator) leak:1). Shut off the water supply at the main stop-cock this time. Drain system at the kitchen sink.2). Open the faulty chrome tap and drain the water away.3). Undo the nut at the rear of the valve and remove it.4). Have a new one ready of course you can now fit the new chrome tap. Use the old nut and olive if you want. If the olive looks damaged either use PTFE tape or maybe even cut the pipe back and fit a new nut and olive on the new end. Stratford Plumbers fit new 90 degree chrome isolators.