By following the author's style it is meant to trying to keep as close as you can to the choice of words and overall style of writing of the author, surely it is impossible to be a carbon copy of the production of someone you even do not know in person.
Basically you will have to do it the hard way, read the story, take some notes on vocabulary used, how the characters behave, how detailed the background is, and then, re-do the ending.
Once I was told that when one writes something it normally means that a great deal of what as written before will never come into the open, that is, writers try, try and try until they get what they believe is at least satisfactory.
