Removing paint from wood
There generally is no "easy" way to remove paint from wood, but there are several ways that take some time and patience.

A safe way that involves not using chemicals like paint or lacquer thinner would be to get a fine to medium grit sandpaper and rub the surface clean of any paint dust.  I assume that you had recently painted this so the chances are exceedingly low that this is lead paint, but if you live in a country that still sells lead paint or you suspect that the paint you used contains lead, then I highly suggest not sanding this and instead using a thinner.  You don't want to be breathing in lead paint dust, especially if you have pregnant women, children or animals in the house.

It seems there is a round area that meets with the flat of the trim, and sandpaper is not going to get into this crack very easily.  I advise carefully using the sharp end of a paint scraper to gently remove any paint in any crevices that you cannot reach with sandpaper.



Just use this to get into areas that you cannot reach with the sandpaper since you don't want to risk gouging the wooden trim.  If you do cause some damage to the wooden trim then applying a simple wood filler and sanding to match the trim should easily hide any damage.  Make sure that you get a wood filler that can be painted and stained.

When you are finished you will want to remove any paint dust from the area with a wet cloth or sponge and let completely air dry.  At this point you will be able to re-stain the affected area.  Take a picture of the wood trim and visit your local hardware store, they can generally help you find a stain that will match with the existing color and finish of the existing wood trim.  Follow the directions on the can for applying the stain and you should look good as new.