How do you get rid of black mold in bathroom?

Black mold is not a good thing in your house. The cleaning process may take a few different processes. First, clean all of the surfaces in the bathroom as you normally would, scrubbing off as much as you can. Rinse. Put the shower curtain into the washing machine with a little soap and use the normal, warm water cycle. (Rehang the curtain when you are finished cleaning--it will hang back out into shape when you next shower.) If mold remains--still is black or orange where there should be white--pour some bleach into a cup and then drizzle the bleach over the areas that need it. You should have good ventilation while doing this--open the window and/or run the fan. Let the bleach sit for a few minutes while you mop the floor. Rinse off the bleach solution.

Now, look at the situation--is the tile reasonably clean? Is the wall behind the tile solid? Does the caulking need replacing? Is there a leak somewhere in the room? These things may need repair sooner than later, but at least now you have a bathroom with clean surfaces.