New dirt and bigger pots for house plants

During my detailed cleaning in the house, it happens, that I find a forgotten plant in a window behind a curtain.

Very often they look ready for the compost, and sometimes that's also the only option.

But that's a sad ending for a plant, that might be valuable of sentimental or other reasons.

The first thing we tend to do is to attack the obvious: cut off everything that seems bad.

Don't.

Start by watering the plant and let it drink up every drop possible without drowning it. I sometimes put big plants in the shower. That way the plant is m watered and the dust is washed off at the same time. I brush it over several times during a morning, and let all excess water run off the leaves during the afternoon.
Be careful not to water so much, that all the fertilizing elements get drained oh the soil. Water the surface. Let the surface suck up the water. Then water again a bit later. 

If your pour out a swimming pool of water on top of hard solid dry dirt, it'll wash right off the surface.

It is in fact a good idea for almost all types of plants: to give your plants a shower once in a while. Not just for a perfect thoroughly watering, but also to clean the leaves so the plant can breathe.
And yes - oh yes it does... Breathe.

Back to the half dead plant...
When the plant has got all the water it can hold, the leaves starts to wake up as the juices rises in the plant.
When this happens, I start to cut off the dead parts. And not before that.

When the leaves lack water, they are much more fragile. So make sure it's filled with water not just in the soil, but in the plant itself, before you start handling it.