Cut the stems to the base.
Once a week take the inner pot out and either soak for 10 minutes or use a jug to pour tepid water through the pot a few times.
You want the roots to go from silver to green. Don't allow the roots to sit in water through the week.
They like the leaves to be misted with either water or an orchid spray.
Change the location in your house, a temperature change triggers new growth-I cycle mine round the house.
There are some brilliant YouTube videos on phalaenopsis orchids.