You can put it in the frig. When it gets cold the fat will solidify on the top. You can then break it off.

What is kitchen paper? Do you mean paper towels?

Let it cool slightly then place a sheet of kitchen paper on top. Remove then place new sheet. Do this again. You may need 3 sheets but it's very effective!

A spoon or even the tip of a knife will work. Is it a lot of fat? Are you very much avoiding fat? If it's only a little, it'll be delicious when reheated. I'm not advocating unhealthy eating here, but hey.

If you are going to cool the stew then reheat it, the fat will solidify and can pretty easily be removed.

I generally just skim most of it off with a large spoon.